The British Infrastructure Group (BIG), a group of more than 40 cross-party MPs led by former Conservative Party chairman Grant Shapps, has issued a report urging the government to decide on whether Heathrow or Gatwick should be allowed to expand.

The group’s Gate Now Closing report said there needed to be an “urgent and immediate decision on hub airport expansion”.

New prime minister Theresa May said last week that a decision on airport expansion will be made in “due course”.

A decision had been due to be announced this summer but it has been delayed again until “at least October” following the Brexit vote last month.

“The problem of capacity at the current hub, Heathrow, is causing substantial damage to the industry as a whole,” said MPs in the Gate Now Closing report.

“It erodes confidence in the government’s stated ambition of growing the economy and our international trade. The evidence has been gathered by the Airports Commission - now a decision is needed to show the new leadership’s mettle.”

BIG is also calling for the expansion of the UK’s regional airports and for the government to “progressively” lower APD.

“Britain’s major aviation tax, APD, is many times the rate of similar taxes in European competitors and trading partners such as the US,” said BIG in the report.

“APD hinders exports, distorts the market, and hits small carriers hard. BIG believes that a lowered rate, by boosting the wider economy, would eventually be cost-neutral for the Treasury.”