According to a report in The Times, civil servants in Whitehall have “cleared all the hurdles” for a decision on whether Heathrow or Gatwick should be allowed to build a new runway.

Cameron, who is leading the “Remain” campaign to stay in the EU, is being urged by both civil servants and some colleagues within the Conservative party to exploit a “window of opportunity” if the referendum vote on June 23 goes his way.

Former London mayor Boris Johnson, who is backing the “Leave” campaign, is also one of the most vocal opponents of Heathrow expansion.

Johnson is expected to receive a cabinet role in a post-referendum reshuffle but sources suggest Cameron could make a decision on airport expansion before this reshuffle takes place should the UK vote to stay in the EU.

Cameron had originally promised to make a decision on a new runway by the end of 2015. But this was postponed until summer 2016 as the government wanted more work carried out on the environmental impact of the runways.

The government-appointed Airports Commission has recommended that Heathrow should be allowed to build a third runway.