A new war of words has broken out between Gatwick and Heathrow as D-Day looms over which will get a new runway.
This time, the airports' chiefs are at loggerheads over pollution, following the end of a public consultation on air quality.
The Commission, which was set up to consider rival bids for airport expansion and is expected to make a final recommendation shortly, closed its consultation on air quality on Friday (May 29).
Gatwick chief executive Stewart Wingate said: "Air quality concerns have prevented Heathrow expansion in the past and the air quality in west London continues to exceed the legal limits and is forecast to do so until beyond 2030.
"The country cannot afford to make the wrong choice and risk years of delay on a project that is eventually halted because of its unacceptable impact.
"There is now an alternative - Gatwick has never breached legal air quality limits and would operate comfortably within these standards with a second runway."
The UK's Supreme Court recently gave the Government until the end of the year to draw up plans to meet EU pollution limits - a ruling Mr Stewart Wingate described at the time as a potential "showstopper" for a third runway at Heathrow.
Heathrow has said traffic on the M4 and M25, most of which it claims is unconnected to the airport, is largely to blame for pollution levels north of Heathrow.
It says its own forecasts and those of the Airports Commission both show air pollution around Heathrow would fall within EU limits by 2030 even with a third runway.
However, the airport has accepted it does have a part to play in reducing air pollution locally.
It recently published a 10-point plan for a greener Heathrow, in which it said it would look at creating a low emissions zone around the airport.
Matt Gorman, Heathrow's sustainability and environment director, said: "The Airports Commission air quality analysis has confirmed an expanded Heathrow will go beyond meeting local air quality limits.
"We worked with local communities and campaign groups so that our new approach to Heathrow expansion would deliver the right environmental solution as well as the right solution for the economy. Now let's get on with it."