Lord Adonis, head of the National Infrastructure Commission, told the BBC that the government should act now, 14 years since the original decision in principle was taken to proceed with Heathrow.

He told the BBC’s Today programme: "At the moment, Heathrow is running at capacity. We cannot be open for business if you can’t get in and out of the country.”

Theresa May’s government approved the third runway at Heathrow last October, but the issue was not included in the Queen’s Speech, an outline of what the government will do in the next parliament.

May no longer has a majority in the House of Commons and many in her own party with constituencies close to Heathrow are against its expansion, which potentially means an embarrassing revolt for the government.

Key opponents with seats near Heathrow include Foreign secretary Boris Johnson, Liberal Democrat leadership candidate Vince Cable and Zac Goldsmith, who regained his seat for the Tories on June 8 after resigning it when the third runway was approved.