Martin Handyside claims that rising costs and insecure tenures have left some with no choice but to face homelessness.
Martin, 67, says he has been sleeping in his car since May when he was evicted from a shared house where the landlord wanted to increase the rent.
The retired brewery worker and cleaner showers at a local gym and says that he has been ill in the time he has lived in his car.
Martin told the BBC: “It’s absolutely freezing, it would help if I had somewhere warm to stay.
“Your life is in danger really, sleeping out there in the car.
“I don’t feel safe, I really don’t.”
Martin adds that on his combined state pension he could afford to rent another room in a shared house for about £800 a month, but has struggled to rent privately.
He says his age is proving to be a barrier, with many house shares targeted at young professionals.
The pensioner claims that he contacted Wandsworth Council which had not offered accomodation.
But the council got in touch to offer temporary accommodation after being chased by the BBC.
Aneisha Beveridge, head of research at Hamptons, says: “Most people in their 60s, 70s and 80s do own their own houses but as soon as you start to look below that, people are less and less likely to own.
“It becomes harder to buy the older you get, so that is what is playing out in this research in terms of thinking that more people will rent in the future.”
London‘s rents in particular are at record levels so there are concerns those on a pension will struggle.
The number of London rental households with people over the age of 65 is rising, according to ONS data analysed by property specialists Hamptons.
It says there were about 46,500 in 2011 and several thousand more by 2021.
And by 2033, the figure is predicted to be above 70,000.
It comes as renters older than 55 are struggling to afford basic living costs such as buying food or heating their homes, research shows.
Two-fifths of the age group are regularly running out of cash to pay for items such as paying for much-needed clothes, a study has found.
The report highlights a “ticking time bomb” of elderly people in privately renting hit by high costs in the coming years.
Labour’s Angela Rayner said renters of all ages have never been so exposed and “desperate for action” amid a housing crisis.
Those who are pre-retirement renters – aged 55-64 – have risen quicker than any other group with a huge increase of people living in homes they can’t afford.
Figures show half of older private renters are worried about getting into debt to cover their rent.
One in four have been been asked to leave their home in the past five years.
A new report reveals more than 850,000 people are living in expensive but insecure rented homes, polling by the National Housing Federation shows.
Abigail Wood, chief executive of Age UK London, says: “It makes things difficult for those older Londoners, and the lack of security of tenure that can come with renting privately means this is going to be a real worry for large numbers of older Londoners.
“We see there are higher rates of poverty amongst the older people in London who are renting compared to those who own their own housing, which is not surprising.
“It is both a cause and a consequence.”