The next steps in the work to decide on future UK runway capacity are being outlined today by the head of the Whitehall-appointed Airports Commission.
Chaired by former Financial Services Authority chief Sir Howard Davies, the commission has already shortlisted Heathrow and Gatwick Airports as possible sites for a new runway by 2030.
Today, at a major aviation conference in London, Sir Howard will speak about the commission's work towards a definite runway recommendation - to be made in a final report in summer 2015.
Also speaking at the conference, is London Mayor Boris Johnson's aviation adviser Daniel Moylan.
Mr Johnson is bitterly opposed to a new, third runway at Heathrow and favours, instead, a brand-new airport in the Thames Estuary - a scheme dubbed "Boris Island".
The commission excluded any of the estuary plans in its shortlist published last month but have said it would further study an Isle of Grain airport option.
Earlier this week it was revealed that Mr Johnson had written to Sir Howard asking him not to sideline the estuary plan.
Launching the commission's interim report last month, Sir Howard said the estuary airport plan could cost as much as £112 billion - much more than either the Heathrow or Gatwick options.
He also said the construction challenge in building a new estuary airport would be "massive".
An extra, third runway at Heathrow was given the go-ahead by the Labour government in 2009, but scrapped by the coalition Government when it took power in May 2010.
In a letter to Transport Secretary Patrick McLoughlin, the 2M group comprising a number of local councils said that Sir Howard had shortlisted potential sites for new runways before assessing their environmental impacts or delivery costs.
Ray Puddifoot, leader of Hillingdon Council in west London and a 2M spokesman, said: "In any scenario expanding Heathrow will have the most severe noise and air quality impacts. Its location guarantees this. It's astonishing that Heathrow can be shortlisted without understanding the true costs of mitigating the environmental and community damage that expansion would bring."
Ravi Govindia, leader of Wandsworth Council in south west London, said: "Sir Howard is proceeding as if people's attitudes to noise hadn't changed since the early 1980s. We have urged the commission to order a new social study now so that the noise standards are based on credible evidence of community impact."
Yesterday the London Assembly passed a motion reaffirming its opposition to the expansion of Heathrow and suggesting more use could be made of spare capacity at other airports serving south-east England.
Assembly member Caroline Pidgeon, who proposed the motion, said: "I am really disappointed to see Heathrow back on the table. "