It looked like group therapy. One late summer day, Sadiq Khan, the mayor of London, sat with a group of faith leaders and clean-air campaigners in a small circle in the near-empty hall of a suburban church.

The moment was meant to be one of celebration, for Khan and for London. He was marking the creation of the largest clean air zone in the Western world through the expansion of restrictions on polluting cars to cover the entire British capital, a city of 8.9 million people. Instead, the gathering was reminiscent of a group of conspirators meeting under siege. “I’m very moved to be here,” said Rabbi Jonathan Wittenberg, brow furrowed, tone hushed. He praised Khan’s “courage.”

Sitting beside the mayor was Rosamund Adoo-Kissi-Debrah, a 53-year-old teacher turned campaigner. She reflected on the tragedy that had turned her into an activist. Just over a decade ago, her daughter Ella died of severe asthma caused by the pollution from the busy road by their home. “She drowned in her own mucus,” Adoo-Kissi-Debrah said, her voice quaking. ” I will always be sorry.”

Khan’s mouth collapsed into a deep frown. Tears welled in his eyes. His own daughters are roughly the same age as Ella would have been today. When I talked to him later, he said it was Ella’s death that served as the “catalyst” that made clean air a central focus of his mayoralty. “Rosamund changed my life,” he said. “Ella changed my life.”

On its surface, Khan’s clean air zone is hardly the stuff of revolution. Called the London Ultra Low Emission Zone (ULEZ), it imposed a daily charge of £12.50 (about $15) on highly polluting vehicles traversing the central parts of the capital and enforced the sanctions with roadside cameras. Yet its expansion in late August has distorted U.K. national politics and Khan’s political prospects, and would even come to pose a threat to his personal safety. 

The new pollution charge has been met with a seething public backlash — one I would later encounter firsthand in a village on London’s furthest reaches.

According to a person close to the mayor — who, like others in this article, was granted anonymity to discuss sensitive matters — anti-ULEZ protesters have regularly turned up at Khan’s South London home, including when his two daughters were there alone. For several days, a caravan was chained outside his house bearing slogans and artwork that included swastikas. Protesters targeted his family for abuse at public events. 

A town hall meeting in early November had to be moved to City Hall for security reasons. During the meeting, a man yelled that, centuries ago, Khan would have been hung from the “gallows.” Police have regularly searched the mayor’s house and car in response to written notes claiming explosive devices had been planted. In October, a letter came in the mail, addressed to him, with a bullet inside.

“I’ve received death threats on a whole host of issues, from my views on Trump, to my religion,” Khan, who is a devout Muslim, said. “This is the latest incarnation.”

The vein of opposition Khan has opened is deep, and filled with rage — even among some who drive modern cars and would not be affected by his policy. The mayor acknowledges his decision to go forward with the expansion has complicated his bid for a third term in May — and raised the stakes exponentially.

The policy arguably cost his center-left Labour Party a seat in parliament in a June by-election — leading to a public rift between Khan and the party’s leader, Keir Starmer. In response, the U.K.’s Conservative Prime Minister Rishi Sunak criticized Labour’s “war on motorists” and ditched several national climate policies.

Around the world, mayors are watching Khan’s struggles intently, weighing their own willingness to take on the polluting cars. These machines may produce greenhouse gas emissions, cancerous particulates, noise pollution and congestion, but cutting down on their use challenges decades of public and private investment premised on their widespread availability. And, perhaps, more fundamentally, it runs against a sense of personal freedom fattened by a century of auto-capitalism and the dream of the open road.

In short, cars have become as politically toxic as their fumes are dangerous to human health. Even the most tentative efforts to rein in cars in cities like New York, Paris, Madrid and Buenos Aires have opened new, growling fronts in the culture wars. In his surge for a second term as U.S. president, Donald Trump has relentlessly attacked his likely opponent Joe Biden’s push to expand electric vehicle use.

“Sustainable mobility has rapidly become a politically divisive matter,” Milan’s mayor Giuseppe Sala said in an emailed answer to a list of questions about his friend and peer in London’s City Hall. “It should not be.”

Khan believes he can convince Londoners that cleaner air is worth some sacrifice, and the polls favor him to retain his place in May. But experts and City Hall staffers warn London mayoral elections are typically tight affairs. If Khan were to lose, the effect on the confidence of city leaders around the world would be “catastrophic,” Sala said. “Sadiq has led the way … It would mean that the most advanced city in the world on this matter has not been able to see the benefits down the line.”  

‘Skin in the game’

I met Khan at his new headquarters in east London. The mayor is 53 years old — the same age as Adoo-Kissi-Debrah — and the son of Pakistani immigrants. He has neatly barbered grey hair and speaks in the fast-talking vernacular of his beloved South London. Like many  Londoners, he gives the impression he’s trying to sell you something you didn’t know you needed.

Standing at the window of an angular second floor meeting room, he launched into an unsolicited and spirited pitch about the upsides of his decision to move City Hall from a prestigious Norman Foster building near Tower Bridge to a dockland in the city’s eastern hinterlands. The relocation, he said, could bring renewal to a part of London that is synonymous with economic depression.

Unbeknownst to most of his constituents, Khan is a minor star of the global climate movement. He is the co-chair of a network of mayors from 96 of the largest cities on Earth, called C40 Cities. That group will play a key role in the COP28 climate summit in Dubai starting on November 30. Partly in anticipation of a Trump redux, mayors will use the meeting in the Gulf to highlight how cities can continue to implement climate policies when everything goes wrong at the top.

Despite his zealotry today, Khan admitted being a latecomer to the climate cause. When he was still a member of the U.K. parliament, Khan said he voted in favor of expanding Heathrow airport “without any real thought about it.” He drove a 4×4. The impact he might be having on the environment and people’s health “just wasn’t really an issue” for him.

In 2015, Khan was diagnosed with late onset asthma, contracted while training for the London marathon — a political stunt, he readily admits. This awakened him to the damage air pollution does to the human body. Cancer, heart disease, dementia and respiratory disease are all among a full diagnostic manual of maladies that can be attributed to the toxic particles and gases emitted from vehicle tailpipes. 

But it was not until he met Adoo-Kissi-Debrah that clean air became a personal crusade. After he was elected mayor in 2016, Khan had been warned by his staff not to meet her. She was viewed by City Hall as potentially dangerous, a Green Party member and a grieving parent who was seeking a new coroner’s inquest, in all likelihood so she could sue the city.

Ella died in 2013, aged 9. She had contracted asthma two and a half years earlier. In that short time, she was admitted to the hospital more than 30 times, suffered five heart attacks and was placed on ventilators. It was the most severe case her doctors had ever seen. 

Her story framed the air pollution problem in terms Khan could easily understand from his work as a human rights lawyer and MP. In Ella, who was Black, he saw how air pollution was killing the poorest Londoners: people of color like him. “I’ve got skin in the game,” he said. He likened the impact of Ella’s story to the way the murder of black teen Stephen Lawrence in 1993 put a face to racism in the London Metropolitan Police service. “Ella humanizes air pollution in ways that no speech or article or interview I can do,” Khan said. “The struggles she’s had — it’s gotta be worth something, right?”

Khan was just one of many politicians Adoo-Kissi-Debrah had courted in her quest, first for the truth about Ella’s death, then for changes that could bring some kind of meaning to the loss. She could tell Khan was deeply affected by her story. They met again and she introduced him to her other kids: teenage twins Robert and Sophia who lost their big sister when they were five. “I think when he met my children, that was a game changer for him,” she said.

Instead of avoiding Adoo-Kissi-Debrah, Khan teamed up with her. About 4,000 Londoners die early each year from bad air, but none have ever had it formally listed as a cause of death. Khan and Adoo-Kissi-Debrah felt that a coroner’s finding tying Ella’s death to air pollution would transform the conversation. Working with her campaigning lawyer Jocelyn Cockburn, an old law firm colleague of Khan’s, and the physician Stephen Holgate, they built a case to overturn the original coroner’s finding.

Seven years after Ella’s death, a new report was issued. It found toxic air from the busy road near her house had caused and worsened Ella’s asthma. The decision spurred clean air campaigners across the country who had a new, watertight legal finding to ram home their public health message. They pushed city authorities from Portsmouth to Aberdeen to introduce their own clean air policies. 

Adoo-Kissi-Debrah immediately lobbied Khan to expand the ULEZ to the rest of London. He disappointed her by first opening the policy to public consultation. “He wanted to do everything prim and proper,” she complained. She revved up her lobbying to ensure he followed through. “Did I lay it on? Oh, hell yes,” she said. “Sadiq knows not to disagree with me — I’m only joking.”

Adoo-Kissi-Debrah’s children did sue the city over their sister’s death. The case is ongoing. Meanwhile, the mayor moved to expand ULEZ at the end of the summer of 2023.

Information battle

Nobody in City Hall could have predicted how badly things would go.

ULEZ had been, in many regards, a Conservative Party policy. It was created in 2015 by Khan’s predecessor at City Hall, Boris Johnson, who called it “essential.” In 2020, the Conservative government pushed Khan to expand the ULEZ to cover all of inner London as part of a list of conditions for a pandemic bailout of London’s transport authority. Khan, who complained he was given few resources with which to ease the economic burden on drivers, expanded it, then expanded it again. But still, he believes the entire thing was a set up. “Without a doubt,” he said. “For party political reasons the government has chosen to turn this into political football.” (A Transport Department spokesperson said: “It is for the Mayor to justify the ULEZ expansion.”)

If the expansion of ULEZ was a trap, Johnson’s resignation as a member of parliament was the perfect opportunity for the Conservatives to spring it. Johnson, who had gone on from City Hall to become prime minister, vacated his seat in June, triggering a by-election in his constituency, Uxbridge and South Ruislip — on the border of West London, an area where the clean air zone was due to expand. Steve Tuckwell, a local councilor, was selected as the Conservative party’s candidate and launched immediately into a month-long campaign with a single focus: “Stop ULEZ.” 

The mayor found himself trying to inform the public about his clean air push in the middle of a political campaign and a supercharged information war. Advertising data on Facebook collated for POLITICO by Ben Collier, a researcher at the University of Edinburgh, shows interest groups on both sides took out hundreds of ads costing tens of thousands of pounds in 2023, dividing Londoners along culture war lines.

The C40 Cities coalition that Khan chairs paid for 78 separate ads, targeting people with university degrees, those who liked animals, those who cared for children. Anti-ULEZ ads were aimed at gamblers, tradespeople, nurses, cleaners, car enthusiasts and people who watch the working class soap opera “EastEnders.” A watchdog group called Valent found evidence anti-ULEZ posts may have been boosted by thousands of alleged fake Twitter accounts. No source of funding to buy the accounts was identified. 

The online campaign was matched with a blizzard of leaflets, delivered through doors in West London. One, from the Conservative Party, falsely claimed that air pollution had increased during Khan’s tenure. Some of these, of untraceable origin, promoted conspiracy theories that claimed ULEZ was part of a plot to lock Londoners into their immediate neighborhoods.

As election day approached, the mayor and his staff became increasingly concerned they were losing the argument. Labour campaigners knocking on doors were meeting angry Tesla drivers who thought they were going to have to pay the charge. “The Conservatives are just spreading misinformation,” Khan complained bitterly. (The Conservative Party did not respond to a request to comment.)

Meanwhile, City Hall was muzzled. The ULEZ expansion was facing a legal challenge, and the mayor’s office, as a party to the case, was advised that it risked losing if the court felt it was trying to sway public opinion. At the same time, rules governing communications by public bodies during elections forced the city authority to suspend much of its advertising in Uxbridge aimed at dispelling common misunderstandings about ULEZ.

Worst of all, the campaign drove a wedge between Khan and his party. Many of Labour’s outer London branches opposed the ULEZ expansion on the grounds that it would disproportionately affect working class people with the oldest cars, or tradespeople getting to work. Ahead of the by-election, there were “difficult conversations” between City Hall and Starmer’s office, said a Labour Party figure.

The mood in Khan’s office darkened further when the Labour candidate Danny Beales recanted his earlier support for ULEZ, telling a hustings event it was “not the right time.” The story of a split in the Labour Party exploded across national media. Two days later, Starmer backed Beales’ position and, when Labour lost the by-election by 495 votes, he said Khan should “reflect” on the outcome.

Khan, who calls himself “a tribal Labour guy,” insists the affair hasn’t dented their friendship — it was Starmer’s birthday a few days after the ULEZ expansion and the mayor made sure to give him a call. But two of the most senior Labour politicians in the land remain at odds. Khan thinks Labour “accepted the Tory narrative,” he told me. “If the public is only hearing one side of the story, you can’t be surprised if they believe it.” (Starmer’s office declined to respond.)

Khan has been criticized, even within his own Labour Party, for failing to win the public’s support for the clean air policy. Today, 40 percent of Londoners oppose the expansion of ULEZ — many more than the number of people who will be directly affected by the charge. Khan said that if he couldn’t win them over by next year’s mayoral election, it would be down to his “failings as a politician.”

Similarly, questions have been raised about why a payment for junking noncompliant cars was initially only available to the poorest households. Khan won the court case against ULEZ just days after Labour lost the election. Almost immediately, he announced he was expanding the scrappage scheme so that all drivers of the most polluting vehicles could access at least £2,000.

If it weren’t for the court case, he told me, he might have done it earlier.

A lynching

On a Saturday in October, I set out amid torrential rain to track down the legendary anti-ULEZ voters who had managed to drive a wedge through Labour, flip an election and reverse years of Conservative climate policy.

For weeks, I had scanned dozens of Facebook groups organizing the resistance. Many posts were directed at the mayor in deeply personal terms. Administrators constantly warned against outright racism lest the sites be shut down.

A protest was planned in Biggin Hill, a village on the very furthest reaches of southern London, surrounded by fields and a small airstrip. Stepping off the bus — there are no other transport links — I had expected a noisy handful of people. Instead, at least 200 protestors had gathered in, as they say in the U.K., the pissing rain.

The overall effect was like walking into some kind of metaverse outgrowth of the Facebook groups. There were leaders with megaphones directing the chants — one of them a jaunty reprise of the wartime classic: “Who do you think you are kidding, Sadiq Hitler?” There were people in dinosaur costumes for no discernable reason. A man with three fingers on one hand stood in the road wearing a suit with a cardboard coffin on his shoulder with the word “DEMOCRACY” written in blue down the side. 

The Biggin Hill protestors didn’t stop with signs and chants. At the intersection where they gathered there was a traffic light on which a camera had been set to catch drivers of polluting cars. By the time I arrived, the thick metal post had been sliced through the middle. Doubled over, the traffic light’s heavy head touched the pavement as though in prayer.

Later, the camera was subjected to what can only be described as a bizarre kind of lynching. In front of a huge picture of Khan’s face with the word “LIAR” printed across the forehead, the stolen camera was hoisted up on a noose while the crowd bayed. Police officers watched passively. Reform UK mayoral candidate Howard Cox — a pro-car campaigner who has successfully fought government fuel duty rises for years — minced about in front of it, posing for photos, saying loudly: “I don’t approve of this.”

According to the Metropolitan Police, 987 ULEZ cameras have been stolen or damaged since April. Five people have been arrested. A vigilante group calling itself the Bladerunners claims credit.

While I was at the protest, a thickset man with generously applied tattoos sidled up to me to enquire if I was a reporter. He was, he told me, a scrap metal dealer. He said he’d never pay the ULEZ charge because he took the license plates off his van when driving in the zone. I asked him if he would ever steal or damage one of the cameras.

“I deal in scrap metal,” he said. “What do you think?”

I didn’t understand.

“I reckon I get eight phone calls a day to collect ULEZ cameras for scrap metal,” he said.

“From the council?” I asked, stupidly in hindsight.

“No!” he said, looking at me as though I might need help finding my way home. “From the people that have cut them down.”

He explained that he drove back and forth across London collecting not just the cameras, but the valuable metal they were attached to, which he would shred and sell. He said he gave the vigilantes £100 for the metal and disposed of the hated cameras.

“I pay for them, off the people, and then I chuck ‘em in the pond,” he said. “I benefit,” he added with a chuckle. He told me he had personally disposed of a hundred cameras in this manner.

He would not give me his name.

Because of the ULEZ protests and other threats, Khan has one of the highest levels of security protection available to a politician in the U.K. His security detail often uses “dummy” vehicles that roar off to give the impression Khan has left an event, while he in fact remains. On a visit to a Brixton community scheme for disadvantaged school kids in October, I saw stocky men with earpieces fan out around the mayor as he made dad-level chat with two teenage girls about their love of trap dancing. 

The degree of concern among Khan’s staff for their own safety is revealing. Adoo-Kissi-Debrah said she felt nervous when her children were next to him. Khan’s family have been confined to their homes, he said, and they sometimes couldn’t go out even to walk the dog. In May, he told the Guardian that he suffers from PTSD.

Car vote

It would be a mistake to focus solely on the extreme views and behaviors of ULEZ’s most vocal opponents. For every conspiracy theorist or self-incriminating vandal at the protest in Biggin Hill, there were many more people with genuinely held concerns about how Khan’s policy was affecting their lives. Policies like ULEZ are blunt instruments, designed to change the behavior of millions of people. Unintended consequences are inevitable.

By the side of the road in a yellow vest was Dave Telford, from nearby New Addington. He uses a wheelchair and has a severely disabled 12-year-old son with Down syndrome and life-threatening epilepsy. Sometimes his son can have two or three seizures in a week, and often requires hospitalization. Because the ambulances won’t take two wheelchairs, Telford follows behind him in a Citroën minibus modified for a disabled driver. “It’s just desperate, desperate, desperate,” he said. “If he goes to hospital, and he dies, we won’t be there. Because we can’t keep paying £12.50 to go down the hospital.”

People with disabilities have until 2027 to comply with the new clean air regulations. But three years and £10,000 from the scrappage scheme won’t get Telford anywhere near the cost of replacing and fitting out a new vehicle with the hydraulic ramps, nursing equipment and other fittings, he said.

I also spoke with Christine Dawson, a pensioner who worried she’d have to go into debt to replace her car. “It’s my freedom,” she said. Sinead O’Shea, a financial administrator, said her vehicle complied with the rules but that ULEZ had isolated her community. “I’m a Labour supporter, but I won’t vote Labour because of him now,” she said of Khan. Josie McDonald, a grandmother of seven from Bromley, said she received £90 per week in her pension and had stopped being able to help her kids with childcare. She’ll be voting for Reform, she said.

Next year’s mayoral election is unlikely to hinge solely on an anti-ULEZ vote. But the opposition will provide the Conservative contender, London Assembly member Susan Hall, with a base to build upon. She has promised to roll back Khan’s expansion of ULEZ “on day one” if elected.

Hall is a relative unknown and “to put it delicately, an accident prone candidate,” said Tony Travers, an expert on London politics at the London School of Economics. Many Londoners first came to know her after it emerged she had liked a post on Twitter, now X, that praised Enoch Powell, a white Tory minister who stoked racial tensions in the 1960s. She declined to be interviewed for this article. 

Khan is favored to win, but “it’s quite competitive,” said Travers. “If the Conservatives had come up with a different candidate, they might easily have won.”

Carrot or stick

With elections approaching, politicians tend to avoid punitive policies that curtail freedoms. But as he prepares to face voters in May, Khan has plowed on, arguing that, in the face of Ella’s death, there is really no other option. 

In the meantime, the national Labour Party is preparing for the general election in 2024 with quite a different strategy. At a POLITICO event in September, the shadow climate secretary, Ed Miliband, disavowed ULEZ, adding later: “I’m about carrots, not sticks.” 

When I asked Khan about this, he shot back: “The carrot is longer life, right? The carrot is not having to do CPR on your child X times a day like Rosamund did. The carrot is less pressure on the [National Health Service] so they can treat other people. The carrot is you not taking time off work because you’ve had an asthma attack.”

Khan still thinks he will win the debate, pointing to a “silent majority” who want clean air and a safe planet. He maintains that most of the opponents of ULEZ will eventually see that their fears are unfounded. “Some of them have got genuine concerns,” he said. “And there’s ways of addressing those concerns, which we’re seeking to do.”

All Londoners caught by the ULEZ charge will be eligible to receive a scrappage fee of at least £2,000 for their old car. It might not be enough to get them a like-for-like replacement. Diesel cars as recent as 6 years old may not be exempted from the charge. During the reporting of this article (the timing was entirely coincidental) I bought a 2001 gasoline-powered Ford Fiesta that complied with the requirements. It cost me roughly £1,700 to get it on the road. But, like most cars at that price point, it’s a rust bucket.

In its purest essence, however, the debate about Khan’s clean air policy isn’t about the cost of a replacement car. As combating climate change moves from setting targets to implementing them, policymaking is entering an era of messy — and contentious — interventions. To meet emissions goals, governments will have to change the ways their citizens consume, fly, eat, work, heat their homes and move around their cities — and they’ll have to convince voters the cost of making those changes is worth it.

When it comes to ULEZ, on one side stands the iconic object of 20th-century capitalism and the individual freedom it has provided. On the other, there’s the freedom to breathe clean air and live in less congested cities. For people across the planet, it’s the freedom to live in a world with a relatively benign climate.

For Khan, and for those around the world watching his prospects, the most worrying aspect of the protest in Biggin Hill might not be the protesters at all. Nine out of every 10 cars in Outer London will not pay a ULEZ charge, City Hall says. But during the hours of the demonstration, the cars rolled through like a line of soldier ants marching in defense of their queen. As they passed, the noise was constant and driver after driver leaned on the horn and let out a supportive wail of indignation.

Mark Scott contributed reporting.