Heathrow expansion has reportedly been given the go-ahead by the Government.
Sources told the BBC that the third runway scheme was chosen when Prime Minister Theresa May chaired a meeting of the airport sub-committee.
Proposals to expand an existing runway at Heathrow or build a second runway at Gatwick were rejected, according to reports.
A public consultation will now be held on the impact of a third runway at the west London hub before the final decision is put to MPs for a vote in the winter of 2017/18.
It is unlikely that any new runway capacity would be operational before 2025.
Mrs May has moved to head off possible Cabinet resignations by giving ministers freedom to speak out against the Government's decision, with the possibility of Heathrow expansion fiercely opposed by Foreign Secretary Boris Johnson and Education Secretary Justine Greening.
Downing Street said any ministers wanting to voice their opposition to the plans would have to seek permission from the Prime Minister in advance.
Ms Greening is expected to give her reaction to the decision in a message to her constituents in Putney, south-west London, a source close to the Education Secretary confirmed.
A number of groups have come out in support of Heathrow, including devolved governments, many business leaders and politicians.
But Gatwick insists it is the only project that can be delivered, citing concern about the noise and environmental impact of Heathrow expansion.
Some 783 homes will have to be demolished for the third runway, according to the Airports Commission.
This includes the entire community of Longford and much of Harmondsworth.
John Stewart, chair of anti-Heathrow expansion group Hacan, said: "Countless residents will be dismayed and distraught by this decision.
"Some will lose their homes. Some face the daunting prospect of living under a noisy flight path for the first time. And many others will get yet more planes over their heads.
"But real doubts must remain whether this new runway will ever see the light of day. The hurdles it faces remain: costs, noise, air pollution and widespread opposition including an expected legal challenge from the local authorities."