A final decision on expanding Heathrow is to be put off until later next year, a report this morning claims.
Prime minister David Cameron will blame the delay on doubts that a third runway could meet air quality standards, the Times reported.
A committee of ministers formed to help make the decision is expected to meet on Thursday.
That would leave no time this week for the full cabinet discussion which Cameron has promised opponents of a third runway at the west London hub.
Ministers would have the chance to make their arguments at the cabinet meeting next Tuesday, two days before the House rises for Christmas.
Heathrow and rival Gatwick expect Cameron to delay making a final decision, according to the newspaper.
Air quality has emerged as a key factor, with the VW emissions scandal adding to doubts that a bigger Heathrow could ever meet EU pollution standards.
Heathrow could be asked to work on a revised public transport improvement plan to reduce to a minimum the additional traffic created by a third runway.
Gatwick would be told to continue working on its bid for a second runway so that as little time as possible is lost if, ministers decide against Heathrow after the additional review.
A Gatwick source said: “The choice is now very clear. Legal expansion at Gatwick so Britain can grow. Or illegal expansion at Heathrow, with Britain losing out again.”
A Heathrow spokesman said: “The Airports Commission … made a unanimous and unambiguous recommendation in June for Heathrow expansion.
“Britain can be confident that our new plan will connect the whole nation to global growth while providing opportunities for the local community and making Heathrow the most environmentally responsible hub airport in the world.”