The Airports Commission has backed a third Heathrow runway, saying it will add £147bn in economic growth and 70,000 jobs by 2050.
The report's release has revived intense debate over the runway's environmental impact.
Downing Street officials say they want to digest the report properly, without making "a snap judgement".
But London's Mayor, Boris Johnson, told the BBC that a new runway would have a "catastrophic" effect.
