Lord Winston has repeated a claim that cycle lanes lead to increased air pollutio in London, an assertion that once again has been firmly rejected by cycling campaigners in the capital.

The Labour peer made his claim in a House of Lords debate yesterday on pollution and vehicle emissions, saying: “The reduction of lanes which traffic can travel down means that more cars are taking longer journeys than ever before at slower speeds.

“The evidence is of course that the internal combustion engine is less efficient and pollutes more at slow speeds, particularly when it is idling.”

He urged the government to provide “figures on the evidence of pollution being greater before bike lanes are introduced than afterwards,” adding, “this is an important issue in the future planning of our cities.”

However, Simon Munk of the London Cycling Campaign told the Evening Standard that there was no evidence to back up Lord Winston’s claim, and that evidence was that dedicated cycling infrastructure improved air quality.

“As a scientist I expect Lord Winston to back up his claims with evidence, all studies so far show that most cycle schemes in London have decreased pollution,” he said.

“Pollution monitors along the Embankment actually show a marginal decrease in pollution levels since the cycle schemes were brought in.”

The peer did not flag up any specific cycle routes that might in his opinion lead to greater congestion and air pollution, but it is a claim he has made before, including in a 2013 debate in the House of Lords.

Mayor of London Sadiq Khan has pledged to increase levels of cycling and walking in the city as well as use of public transport and curb private car use to help combat air pollution.

A spokesman for the mayor said: “Cycle lanes do not cause congestion and pollution.

“With our limited street space it is vital that we encourage more Londoners to cycle, walk and use public transport. These are cleaner and more efficient uses of our roads, with cycle lanes proven to help move people along our streets.

He added: “With London’s population set to expand to 10.8 million over the next 25 years, making our capital one of the best cities in the world for cycling is not only about improving our health, wellbeing and quality of life, it is absolutely fundamental for our future economic prosperity.”

During yesterday’s debate, Parliamentary Under-Secretary of State at the Department for Transport, Baroness Sugg, said the government would “publish our plans for the pathway to zero-emission road vehicles and a new clean air strategy later this year.”

Fellow Tory peer Lord Cormack aked her if she would meet some London taxi drivers, adding: “If she does, will she listen very carefully to what they say has been the result of reducing the lanes on our major roads in London, caused very largely by the creation of cycle lanes?

Baroness Sugg replied that she would be hapopy to do so and added: “The construction of bike lanes and bus lanes and the pedestrianisation of many roads has reduced the available space.

“Of course, cycle lanes are welcome in order to protect cyclists and encourage cycling,” she continued.

She added: “I understand that they have increased congestion, but we want to encourage people to cycle.”