The campaign against the multibillion-pound expansion of Heathrow is on the verge of victory, John McDonnell has claimed, as three court of appeal judges considered fresh legal challenges against a third runway.
The shadow chancellor, who has long been an opponent of expanding the airport in his constituency, said the picture had changed since the previous legal challenge in the spring, as the UK had legislated for a net-zero emissions target by 2050 and declared a climate emergency.
“I think legislatively things have moved and politically, with the current campaigning by Extinction Rebellion, the pressure is on all politicians to recognise this is a project that cannot stand,” McDonnell said. He praised campaigners outside court for their persistent action over many years.
Friends of the Earth is leading the legal challenges on climate grounds against the third runway, which was approved by parliament last year. The court of appeal is hearing five days of challenges against the expansion, which will put 700 more planes into the air each day.
Opening the appeal, Lord Justice Lindblom said the hearing would raise matters of obvious importance, which would be of interest to a national and international audience.
Government lawyers will argue the runway can be built without breaching the country’s climate commitment, according to documents submitted to the court.
The high court ruled in May that the government’s decision to allow a third runway was lawful. The court of appeal is hearing challenges against this decision from parties including environmental NGOs, five local authorities, the London mayor and Greenpeace.
David Wolfe QC, for Friends of the Earth, told the court the then transport secretary, Chris Grayling, had not taken the 2015 Paris agreement into account when approving the airport expansion.
Instead, Grayling limited his consideration of the climate crisis to whether the runway could be made to fit within the existing legal carbon targets of an 80% reduction in greenhouse gas levels by 2050. This would require all other sectors to reduce their emissions by 85%.
Wolfe said these targets had now risen to a 100% reduction in greenhouse gas levels by 2050 following an amendment to the Climate Change Act this summer, giving further weight to the argument that the expansion goes against the government’s climate goals.
The Committee on Climate Change, the government’s statutory advisor, has warned ministers that aviation will be the biggest source of emissions in the UK by then.
Wolfe said the transport secretary should have taken into account the Paris agreement as well as planet-warming gases linked to aviation. “No one can be unaware of the urgent need to tackle climate change,” he said.
For the first time, judges will hear arguments that the expansion of Heathrow airport violates the rights of children and future generations, who will bear the greatest impact of the climate crisis. World Wide Fund for Nature was given permission to submit papers alleging a breach of the UN convention on the rights of the child to the court.
Willie Walsh, the chief executive of International Airlines Group, which owns British Airways, told a press conference in Toronto this week he believed the £14bn runway was unlikely to go ahead because of a growing backlash over the environment.
“I think it is a bigger challenge today than it was a year ago. And I can’t see it getting any easier,” he said.
Walsh has been a longtime critic of the cost of the expansion. Critics say the £14bn price tag will balloon to more than £30bn. The two-mile runway will involve the creation of one of the world’s biggest car parks, with capacity for nearly 50,000 vehicles, the reclamation of 385 hectares (950 acres) of land and the demolition of 761 homes. Part of the M25 will need to be moved as part of the plan.
A coalition of local authorities – Wandsworth, Richmond upon Thames, Hillingdon, Hammersmith and Fulham and the Royal Borough of Windsor and Maidenhead – along with the mayor of London and Greenpeace, will argue the expansion was flawed because ministers failed to properly consider the full impact of noise levels, health and the environment.
Heathrow said in its consultation documents that expansion should not come at any cost. The airport has outlined plans for low-emissions zones and congestion charges to stem local air pollution.
Boris Johnson, who once threatened to lie down in front of the bulldozers to prevent the expansion, has said he will watch the legal challenges with lively interest.