The Mayor of London Sadiq Khan has criticised some “anti-walking, anti-cycling” borough councils as he marked a car-free day across parts of the capital.

An estimated 17 miles (27 kilometres) of road in the city were closed to traffic, with 15 boroughs across the capital also taking part, including Hackney, Islington and Haringey.

But Mr Khan, speaking after he cycled across the usually busy Tower Bridge in central London, said he was frustrated that City Hall was responsible for around 5% of London’s road network, with the majority controlled by local authorities.

Mr Khan said: “It’s really important for us to re-imagine what our city could be like.

“We have persuaded boroughs across London to get involved in this and we think there’s 27 kilometres in London that are now car free.”

He went on to criticise those local authorities that he said were not doing enough to reduce air pollution.

“I’m frustrated by some councils being anti-walking, anti-cycling,” he said.

“There are thousands of Londoners who die prematurely.

“We need Londoners to understand the importance of reducing the pollution on our streets.”

Sadiq Khan cycling on Tower Bridge
Sadiq Khan cycled across the normally traffic-congested Tower Bridge (David Mirzoeff/PA)

Asked if he would consider permanently pedestrianising roads such as Oxford Street and Parliament Square, the Mayor replied: “One of my frustrations is that actually very few roads in London are controlled by City Hall.

“I have argued, for some time now, for the benefits of pedestrianising Parliament Square.

“I want Londoners to just imagine what is possible with fewer cars on our streets.”

The Mayor said that he was committed to raising the number of journeys taken using sustainable transport in order to reduce the amount of harmful air pollution that Londoners currently have to breathe in.

At the moment 63% of people travelling across the city either walk, cycle or use public transport.

Mr Khan said he hoped to bring that number up to 80% by 2041 while suggesting that national government needed to do more to reduce air pollution within the capital.

“We need support from government. Half of the bad air is caused by transport, half is caused by houses, by construction and from the river Thames.

“There are two million Londoners, 400,000 of them children, living in areas where the air quality is illegal – that can’t be right.”