The long-awaited recommendation from the Airports Commission on whether a new runway should be built at Heathrow or Gatwick will be published tomorrow.
Debate has been raging for years about the need to expand airport capacity in south east England, with the two competing airports trying to persuade the Government to take urgent action.
The commission, headed by Sir Howard Davies, will publish its final report and recommendation tomorrow morning, although the Government is not expected to decide whether to accept it for months. The choice has come down to three options - a third Heathrow runway, extending an existing one, or building a second runway at Gatwick.
There have been suggestions the Government could delay its decision until after next May's London mayoral election, which will be dominated by the airport-runway debate if Sir Howard recommends one of the Heathrow schemes. There has been speculation that the report is likely to recommend expansion at Heathrow, but only if the airport meets stringent conditions on air quality, noise pollution and carbon emissions. Gatwick has argued its expansion would be cheaper and more environmentally viable.
Lobby groups here including the Chamber of Commerce are in favour of Heathrow expansion - while Sir Roy McNulty, of Norbrook Laboratories, has argued in favour of Gatwick in his capacity as Gatwick Airport chairman.