Heathrow expansion is likely to ease through a parliamentary vote, according to a poll of MPs.
Research carried out by the airport found that 74% of MPs now back the project to build a third runway, up by seven percentage points since the summer.
The proportion of Conservatives in favour has risen from 71% to 80% over the same period.
Heathrow said this meant that there would be “an overwhelming parliamentary endorsement” for the project.
Prime minister Theresa May formally endorsed plans for a new north-west runway at Heathrow in October after decades of debate over the issue.
But some prominent Conservatives have vowed to oppose the plans, including foreign secretary and former London mayor Boris Johnson and education secretary Justine Greening.
However, the poll suggests that the government has easily enough support to get through a vote.
Detailed plans for the runway will be set out early next year alongside a public consultation.
It is believed that MPs will vote on the issue in late 2017 or early 2018 before Heathrow submits its formal planning application in 2019.
The survey of 130 MPs was conducted in October and November, The Times reported.