Luisa Porritt has said that scrapping the Silvertown Tunnel “has to be a top priority” to tackle poor air quality and the climate crisis.

Speaking at a campaign event today, the Liberal Democrat candidate repeated her pledge to scrap what she has dubbed “Sadiq Khan’s dirty little secret” if elected on May 6.

The project, which will cost around £2 billion, will connect the Greenwich peninsula to west Silvertown via a road tunnel under the Thames with the purpose of easing congestion from the Blackwall Tunnel.

Ms Porritt said: “Scrapping the Silvertown Tunnel has to be a top priority if we’re serious about tackling the climate emergency. London has to play its role in meeting our climate commitments and so the last thing that we should be doing is building a new motorway and adding more cars to our roads.

“We’ve already got enough emissions being contributed from buildings and transport use in our city, so this has to be scrapped.”

She added that it was “a nonsense argument” that the Silvertown Tunnel could ease congestion from the nearby Blackwall Tunnel and reduce traffic in the area.

“We know from every other example of new roads being built that it just means more cars on the road and congestion will pile up again over time. So, it’s not going to solve the problem of congestion of Blackwall Tunnel.”

The Liberal Democrat candidate was joined today by two of her party’s candidates in the London Assembly elections, including Greenwich and Lewisham candidate Chris Annous, who said scrapping the tunnel was his “number one priority”.

The £2 billion project has come under intense scrutiny from locals, activists and opposition candidates, with Green Party mayoral candidate Sian Berry also pledging to scrap it if elected on May 6.

Last week, activists jet-washed the slogan “stop the tunnel” onto the Thames embankment, while this morning The Independent reported details of a letter sent to Sadiq Khan and Transport Secretary Grant Shapps by academics and experts calling for the project to be stopped.

Activists jet-washed the slogan stop the tunnel onto the Thames embankment near the tunnels proposed location

Activists jet-washed the slogan "stop the tunnel" onto the Thames embankment near the tunnel's proposed location

In the letter, experts said it would be “foolhardy” to go ahead with a project “that can only contribute to the UK’s greenhouse gas emission”.

Victoria Rance, a campaigner with Stop the Silvertown Tunnel Coalition, said: “The letter in The Independent today shows the strength of feeling among academics and the top experts who know their stuff about transport, the environment and climate.

“They are saying it should be scrapped. And if the Government and Sadiq Khan can’t listen to them, what hope have we got? I think we really need to listen, and I’m afraid that the protests will not stop after the election.”

A spokesperson for Sadiq Khan’s campaign said that the Silvertown Tunnel “is the only alternative to help reduce the poor air quality and massive congestion caused in the area by the Blackwall Tunnel”.

They said: “It won’t cost taxpayers money but will use the proceeds of a user charge in both the Blackwall Tunnel and the Silvertown Tunnel to pay for a reserved lane for buses.

“It will also provide a free travel route for cyclists and pedestrians to get from one side of south east London to the other.”