The nine-member Constitutional Council ruled on Friday in favour of key provisions, including raising the retirement age to 64 from 62, judging the legislation to be in accordance with the law.
Six minor proposals were rejected, including efforts to force large companies to publish data on how many people over 55 they employ, and a separate idea to create a special contract for older workers.
The decision represents a victory for Macron, but analysts said it has come at a major personal cost for the 45-year-old while causing months of disruption for the country with sometimes-violent protests that have left hundreds injured.
The president’s personal ratings are close to their lowest-ever level, and many voters have been outraged by his decision to defy hostile public opinion and ram the pensions law through the lower house of parliament without a vote.
“Stay the course, that’s my motto,” Macron said on Friday as he inspected restoration efforts at the Notre Dame cathedral, four years after a devastating fire gutted the Gothic masterpiece.
Police were expecting up to 10,000 people to gather again in Paris later on Friday, with the presence of several hundred left-wing hardliners raising fears of more vandalism and clashes that have marred recent rallies.
The Constitutional Council, a short walk from the Louvre museum in the centre of the French capital, has been protected with barriers, and dozens of riot police are on guard nearby.
Al Jazeera’s Natacha Butler, reporting from Paris, said that the development was a big win for Macron.
“But there is no doubt that it has come with a price,” she said, reminding that France saw months of massive protests.
“Macron is facing a situation where he needs to try to rebuild trust with the trade unions, some opposition lawmakers and segments of the French society,” Butler added.
Opponents
It remains to be seen if the months-long effort to block the changes by trade unions will continue, with labour leaders saying they would respect the court decision on Friday and support among regular workers waning.
“The fight continues and must gather force,” the leader of the hard-left La France Insoumise party, Jean-Luc Melenchon, wrote on Twitter.
Far-right Rassemblement National figurehead Marine Le Pen added that the fate of the reform was “not sealed” despite Friday’s decision.
Last month, a strike by Paris refuse workers left the capital strewn with 10,000 tonnes of uncollected rubbish, while train services, oil refineries and schools have been affected by regular stoppages since January.
Some 380,000 people took to the streets nationwide on Thursday in the latest day of union-led action, according to the interior ministry.
But that was a fraction of the nearly 1.3 million who demonstrated at the height of the protests in March.
In a second decision on Friday, the court rejected a bid from opposition legislators to force a referendum on an alternative pension law that would have kept the retirement age at 62.
France currently lags behind most of its European neighbours, many of which have hiked the retirement age to 65 or above.
‘Sustainable’ model
Opponents of the law have said it is unfair to unskilled workers who started working early in life, while critics also said it undercut the right of workers to a long retirement.
The average life expectancy in France is 82.
Macron has repeatedly called the change “necessary” to avoid annual pension deficits forecast to hit 13.5 billion euros ($14.8bn) by 2030, according to government figures.
“I’m proud of the French social model, and I defend it, but if we want to make it sustainable we have to produce more,” he said on Wednesday during a trip to the Netherlands.
“We have to re-industrialise the country. We have to decrease unemployment and we have to increase the quantity of work being delivered in the country. This pension reform is part of it.”