An urgent decision on the expansion of either Heathrow or Gatwick airport must be made by the government, a group of cross-party MPs has warned Theresa May.
Thirty-six Conservative MPs, along with five MPs from other parties, have said continued delay would damage the UK economy.
The MPs, led by the former Conservative party chairman Grant Shapps, belong to the cross-party British Infrastructure Group (BIG).
In a new report, they called for a decision to be made “to show the new leadership’s mettle”.
“This report concludes that the government must select the new hub as a matter of extreme urgency," it said.
“The decision on EU membership has not altered this fundamental fact. We believe this choice should be one of the first across the new prime minister’s desk."
The report also warned that the problem of capacity at Heathrow was causing substantial damage to the industry as a whole.
The proposed runway – estimated to cost £18.6bn – would provide an additional 250,000 flights a year and 120,000 new jobs, according to Heathrow.
Both Heathrow and Gatwick airport have been vying for permission to build an extra runway serving London.
The MPs added that “either Heathrow or Gatwick must expand".
"If Heathrow does so, it will have to fulfil various pledges towards regional aviation, including new domestic routes and a £10m route development fund. If Gatwick expands, it has similar promises to fulfil, though on a smaller scale," they said.
In 2015 the Aiport Commison's report recommended building a third runway at Heathrow as long as there was a cap on noise, a ban on night flights and acceptable performance on air quality.
Decisions to expand the airport have been delayed for years by ministers concerned about noise and air pollution.
Last month, the then transport secretary Patrick McLoughlin said a decision on expansion would not be reached until October, following Britain’s decision to leave the EU.
Ms May’s government includes several MPs who are against the new runway being built at Heathrow.
Opponents to expansion highlighted comments Ms May made in 2009, when she said: “We need a better Heathrow, not a bigger Heathrow. My constituents [in Maidenhead] face the prospect of a reduction in their quality of life with more planes flying overhead, restriction in driving their cars locally and a far worse train service.”
But Heathrow's chief executive, John Holland-Kaye, said Britain needed a positive post-Brexit plan.
“Only Heathrow expansion will help Britain to be one of the world’s leading trade nations – connecting all of Britain to global growth,” he said in a statement.
