Having fewer cars on our roads will close the 17-year healthy life expectancy disparity between poorer and wealthier parts of the borough, according to one London mayoral hopeful.

The Green Party’s Sian Berry, 41, a Camden councillor and former medical copywriter, spoke to the Recorder about her plans to merge Tube zones five and six and zones three and four.

She hopes cheaper fares from Havering’s stations – which would go from being in zone six to zone four – will encourage people to hang up their car keys and drive down air pollution.

The comments come after the Recorder last year revealed a boy born in Cranham will live healthily for 17.1 years longer than one born just 4.2 miles away in Harold Hill.

“Where I’m from in Camden there’s an enormous difference in life expectancy between Hampstead and Kings Cross – there’s lots of reasons for that, one is air pollution.

“People who are poorer tend to live in areas that have more heavy traffic and are less leafy, and that’s a genuine problem.”

Ms Berry hopes to widen the congestion zone and bring in a new low emissions zone to help reduce pollution and balance how much money Transport for London (TfL) makes through Tube fares and the congestion charge.

“People who take trains contribute 40 per cent to TfL’s budget. Drivers only contribute 2.5pc through the congestion charge.

“It’s about balancing it in favour of people that use public transport, which is actually most of Londoners now, even in outer London about one third of families don’t have a car.”

Ms Berry said she planned to “re-write” Boris Johnson’s low emissions zone.

“The low emissions zone Boris has only covers the congestion zone – it’s really inadequate when it comes to protecting the health of Londoners. It’s possible to re-write that so before it comes in 2020 we have a replacement scheme that’s actually going to be effective.”

She said it was also about improving access to healthy food and exercise but admitted “if you are stuck in housing that’s next to a busy road, you can’t take steps yourself to improve you health – you need help from the mayor”.

“It’s making sure there are more of the services you need in walking distance so you don’t feel the need to get in your car,” she added.

“It’s about making it safe to walk and cycle and it all saves money.”

However, the candidate said her party dealt with more than just green issues, with housing at the forefront of her campaign.

“We’re known now for many more issues,” said the candidate, who is looking at building 50,000 homes on top of existing housing estates in London.

“We also do a lot on supporting renters – I want to set up a renters union. I rent my own house so it’s something that’s close to my heart.”

Speaking about building on green belt land, the transport campaigner said there was plenty of brownfield and publicly-owned sites in the capital to make use of.

She said: “I don’t think building on green belt is an inevitability, not for a very long time.

“We’ll have difficult questions in about 10 years time, but for the time being we have no problem finding enough brownfield land, and there’s a lot of public land owned by TfL, the NHS and the police.”

About her chances in the May election, she said: “I’m running to win, I want to be mayor.

“I think we [the Green Party] have got the answers in a more through-and-through, practical way than the other candidates do.”