A vote on expanding Heathrow would win the backing of nine out of ten MPs, according to the chairman of the Conservative 1922 committee.
Construction of a third runway would secure overwhelming support if it was put to Parliament before Christmas, Graham Brady, chairman of the committee of Tory backbenchers, told Bloomberg.
“It’s a dangerous prediction but I think it’s about right,” said Brady after speaking in favour of Heathrow’s expansion at an event arranged by the airport’s operator.
The Labour Party, the Scottish National Party’s 56 MPs and the bulk of Tories all back the plan, he claimed.
But the SNP announced that it remains “neutral” over expansion at either Heathrow or Gatwick.
Some prominent Conservatives, including Mayor of London, Boris Johnson, remain opposed to growth at Heathrow citing concerns over noise and pollution.
Richmond MP and mayoral candidate Zac Goldsmith plans to force a by-election in his constituency over any such move.
“As with all of these things, we have to be sympathetic to local concerns,” Brady said. “But this is a national infrastructure project and most politicians recognise that. It’s a national decision.”
SNP spokesman Drew Hendry said: “We are absolutely neutral at the moment. The Airports Commission report has given Heathrow the nod but it specifically did not rule out Gatwick either.
“The key thing for us is that for too long Scotland has done pretty badly in terms of maintaining routes from regional airports, particularly Inverness and even Aberdeen.
“Ticket prices were routinely higher for Scots going abroad via London.
“The first thing we will be looking for is a fair deal in terms of onward flights. It is costing Scottish consumers much more per head. Onward connections are much more expensive – the prices are ridiculous.”
Cameron has said a decision will be made in the autumn.