Controversial plans to expand Heathrow would effectively create a “new airport” and have “severe” consequences for Londoners, the High Court has heard.
The Government’s approval of a third runway is being challenged by a coalition of councils, residents, environmental charities and Mayor of London Sadiq Khan.
Outlining the case on behalf of five London boroughs, Greenpeace and Mr Khan, Nigel Pleming QC said the plans could see the number of passengers using the airport rise to an estimated 132 million, an increase of 60%.
On Monday, the first day of a two-week hearing, he told the court: “The new development, if it goes ahead, will add, in effect, a new airport with the capacity of Gatwick to the north of Heathrow.”
Mr Pleming added that the adverse effects and consequences for local residents of such an expansion are “bound to be severe”.
The case is being brought against Transport Secretary Chris Grayling by local authorities and residents in London affected by the expansion and charities including Greenpeace, Friends Of The Earth and Plan B.
The coalition claims the Government’s National Policy Statement (NPS) setting out its support for the project fails to properly deal with the impact on air quality, climate change, noise and congestion.
The claimants argue the NPS is unlawful and should be quashed, which would mean the Government would have to start the process again and put it to another vote in Parliament.
Mr Pleming said the building of a third runway at Heathrow, which was chosen as the preferred option for expanding airport capacity in the south east of England, is “politically controversial”.
He told the court Heathrow is the “busiest two-runway airport in the world” and is situated in a densely populated area.
He said: “If the (third runway) is the means of achieving expansion, there will be widespread consequences.
“There will be hundreds of thousands of additional flights each year across central London, and also affecting the south east.
“Thousands of people’s homes will be demolished.
“Hundreds of thousands will experience increased noise, worsened traffic and harmful air pollution.”
He said there were “errors” in the steps leading to the NPS which mean it is invalid.
Friends Of The Earth and Plan B argue Mr Grayling failed to take enough account of the impact on air quality when reaching the decision to approve the third runway.
Lawyers representing Mr Grayling said the claimants’ case is “unarguable” and “premature”, as they will all have the opportunity to make representations at a later stage in the planning process.
Support from Labour MPs helped push through the proposals to expand Europe’s busiest airport with an overwhelming majority of 296 in a Commons vote in June last year.
Mr Grayling said at the time that the new runway would set a “clear path to our future as a global nation in the post-Brexit world”.
Construction could begin in 2021, with the third runway operational by 2026.
Scores of demonstrators gathered outside the court ahead of the hearing, which is before Lord Justice Hickinbottom and Mr Justice Holgate.
Shadow chancellor John McDonnell, whose Hayes and Harlington constituency includes Heathrow, said: “This is an iconic battleground in terms of climate change.”
Zac Goldsmith, MP for Richmond Park and North Kingston, who previously resigned over the Government’s decision before returning to the Conservative Party, said: “It is a massive issue locally, but it’s a London issue.
“If you look at the proposals for flight paths, they are not specific, but they affect most of London.”
Craig Bennett, chief executive of Friends Of The Earth, said: “We absolutely do not see how you can have aviation expansion in the UK… while cutting our carbon emissions by 50% in the next 12 years.”
Executive director of Back Heathrow Parmjit Dhanda, who supports the expansion, said: “There is an awful lot of support for this project.
“It is really important that we see both sides of the argument.
“I think if this expansion did not go ahead, it would be a disaster for Britain in a post-Brexit world.”
A Department for Transport spokeswoman previously said: “Expansion at Heathrow is a critical programme which will provide a boost to the economy, increase our international links and create tens of thousands of new jobs.
“As with any major infrastructure project, we have been anticipating legal challenges and will robustly defend our position.”
A Heathrow spokeswoman previously said: “Our work in delivering Britain’s new runway will continue in tandem with this process following overwhelming support in Parliament.
“We remain focused on the work needed for our development consent order submission in 2020 and we are getting on with the delivery of this project which will benefit the whole of the UK.”