Clues on the future of airports in the south may be revealed today.
The man chosen by David Cameron to investigate airport capacity in the UK will set out what he hopes to achieve.
Sir Howard Davies will also announce on Friday who will sit on the commission and what it will examine.
His report is due in 2015, but the decision on whether to support its recommendations will be taken after the next general election.
In the past few months, businesses have called for greater capacity at airports including building new runways in Heathrow and Gatwick.
The architect Norman Foster and London Mayor Boris Johnson have also put forward plans for a new airport in the Thames Estuary.
The coalition government has ruled out further expansion at Heathrow during the current parliament, many Conservative MPs want ministers to think again as part of a wider review of the future of UK airports.
Sir Howard was asked to look into the issue of airport capacity by Transport Secretary Patrick McLoughlin in September.