Ministers will meet tonight to decide how to respond to recommendations that a third runway should be built at Heathrow.
Prime Minister David Cameron, Chancellor George Osborne and key Cabinet ministers will discuss how to proceed on airport expansion.
The decision will then go before the Cabinet.
It has been widely speculated that the Government is set to announce a delay amid concerns about the environmental impact of a new runway.
Heathrow anti-noise campaigner John Stewart, who chairs the residents' group Hacan, said this would demonstrate "just how difficult it will be to build a third runway".
Mr Cameron has previously said a decision would be made by the end of the year but the promise later appeared to be watered down when No 10 explained that a "clear direction" would be provided.
The Davies Commission recommended the construction of the controversial third runway in a report in July.
Transport Secretary Patrick McLoughlin, Environment Secretary Liz Truss, Scotland Secretary David Mundell, Communities Secretary Greg Clark, Cabinet Office Minister Oliver Letwin and Chief whip Mark Harper will also attend the Cabinet sub-committee on airports to consider its recommendations.
Business Secretary Sajid Javid will miss the meeting because he is on a visit to India and Energy Secretary Amber Rudd is also expected to be unable to attend.
London Mayor Boris Johnson has not been invited to the meeting and no MPs from the capital will be represented.
A Downing Street spokesman said: "The sub-committee will come out with a conclusion which will go to Cabinet."
Mr Stewart claimed a third runway is "unlikely ever to see the light of day".
He said: "The last Labour government tried and failed. And now this Government has run into real obstacles.
"Heathrow would require almost 1,000 homes to be demolished and part of the M25 to be moved and put in a tunnel.
"It would mean a quarter of a million more planes flying over the city with the biggest aircraft noise problem in Europe and could cause air pollution to exceed the EU legal limits.
"Many of these problems won't go away however long the final decision is delayed."
Chambers of Commerce from across the country wrote to Mr Cameron on Wednesday demanding that he approve Heathrow expansion by the end of year.
They warned that any delay raised "grave concerns" about the future credibility of the new National Infrastructure Commission and cast doubt about whether it would have real power to make big decisions.
The letter stated: "Our businesses tell us that ministers' statements on growth and exports mean little if the Government cannot take the tough decisions needed on key infrastructure projects.
"Our businesses want delivery, not more reports and recommendations. We want to see Heathrow expansion approved by the end of the year, as promised."
Speaking during a visit to Cumbria, Labour leader Jeremy Corbyn said his party wanted answers to four questions it had raised about the impact airport expansion would have on capacity, climate change, the environment and noise.
"Those are the questions that have to be answered before any decision can be made," said Mr Corbyn. "Merely putting off decisions isn't helpful - those questions have got to be answered."
Heathrow chief executive John Holland-Kaye said: "The message to the Prime Minister this week is clear - expand Heathrow and unlock growth across the country. Businesses and unions, regions and local communities, politicians from all parties want certainty and to get on with Heathrow's new plan.
"We're ready to deliver the hub capacity this country needs - we will work with the Government to make it happen."