The Airports Commission consultation period over proposed expansion to either Heathrow or Gatwick will reach its conclusion this evening at 11.35pm.
The Commission have looked at whether Gatwick or Heathrow should expand.
The two airports have run fierce advertising campaigns promoting their respective advantages.
The head of the Airports Commission will now write his final recommendation to government, on whether to build a third runway at Heathrow, extend an existing runway at Heathrow, or build a second runway at Gatwick The recommendation is expected to be published in the summer.
The commission had previously concluded that their was a need for one additional runway in South East England by 2030, but did not say where that would be.
It also rejected proposals for an island airport in the Thames estuary, which had been backed by Mayor of London Boris Johnson.
London Live's Alison Earle reports.