A legal challenge claiming the government failed to consider environmental impact for major new roads projects will be heard at the High Court.

Campaigners allege the transport secretary and ministers withdrew plans to reduce CO2 emissions for dozens of upgrades and new projects, including the Lower Thames Crossing in Kent.

Transport Action Network (TAN) say the £27.4 billion second Road Investment Strategy (RIS2), which sets out 50 schemes, ignored climate change targets set by the government.

The group says it expects the Department for Transport (DfT) to challenge the action saying climate change commitments were not "obviously material" to roadbuilding projects.

But TAN director Chris Todd said: "Trying to argue climate change isn’t “obviously material” to approving the largest ever roads programme is like saying public health is not relevant to reform of smoking rules.

"In an audacious attempt to protect his addiction to asphalt, Shapps is now seeking a legal precedent that decision-makers can ignore climate targets.

"This puts ministers on a collision course with the Climate Change Committee, which last week called on the government to adopt a ‘Net Zero Test’ for all policy decisions.

"The DfT’s dodgy defence now risks undermining UK leadership of the COP26 (United Nations Climate Change Conference) climate summit and our international standing.”

The £8.2bn Lower Thames Crossing – a 14-mile route connecting Kent and Essex between Medway and Gravesend – is the largest of the projects included in the government strategy.

Critics say the project will create more than five million tonnes of carbon emissions.

TAN argue the impact to the environment in terms of carbon emissions would be 100 times greater than the government claimed.

The group suggests DfT only considered five of the schemes rather than the whole programme of more than 50, miscalculated carbon emissions by using a period when not all five were open and ignored non-tailpipe emissions from land clearance and construction phases.

Mr Todd added: "If we are serious about tackling the climate emergency, improving quality of life after the pandemic and delivering a less congested future, we need to reduce traffic.

"This case, the biggest legal challenge to transport policy in British history, seeks to do just that.

"A ruling to quash the largest ever roads programme would be historic, not just for the UK, but for communities worldwide seeking to build back better in the run up to COP26.”

Laura Blake, chairman of the Thames Crossing Action Group, said: "We know that the proposed Lower Thames Crossing would create over five million tonnes of carbon emissions, along with all the other negative impacts which we would suffer if the LTC were to go ahead.

"We have many serious concerns about the impacts of the proposed Lower Thames Crossing, and feel it is essential that all the negative impacts of the scheme should be taken into account.

"We are grateful to TAN for bringing this legal challenge on climate grounds against the government's £27bn road building programme, which of course includes the £8.2bn Lower Thames Crossing.

"This case, the biggest legal challenge to transport policy in British history, seeks to do just that..."

"We wholeheartedly support this legal challenge, and appreciate all the hard work by TAN and the legal team."

Rebecca Lush, roads campaigner at TAN, added: “How can ministers expect to be taken seriously if they ignore the carbon emissions from all but 100 out of the 4,000 miles of road the Chancellor announced at Budget 2020.

"It’s as if they are trying to pass off an old banger as a brand new electric vehicle.

"Such extreme fiddling of the figures would put even the dodgiest second-hand car dealer to shame. It’s time to shift this outdated roads plan off the forecourt and onto the scrapheap.”

A DfT spokesman said: “Our road policy contains many elements – a plan for decarbonisation of vehicles, plans for public transport and active travel, and plans for road improvements that utilise low-carbon construction techniques.

"Together, these make a balanced package that is entirely consistent with net zero."

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