Campaigners against the expansion of Heathrow Airport have been given permission to challenge a High Court ruling over plans for a third runway.
Councils, residents, environmental charities and the mayor of London brought four separate judicial reviews of the Government's decision to approve the plans.
The campaigners had their cases dismissed by two leading judges in May.
They were given the go-ahead to challenge that ruling on Monday.
During a two-week hearing in March they argued the plans would effectively create a "new airport" with the capacity of Gatwick and have "severe" consequences for Londoners.
Lord Justice Lindblom granted permission for a four-day hearing at the Court of Appeal in London, which will begin on 21 October.
Giving reasons for his decision, which he made based on case documents without a hearing, the judge said: "The importance of the issues raised in these and the related proceedings is obvious."
The High Court case was brought against transport secretary Chris Grayling by local authorities and residents in London affected by the expansion, and charities including Greenpeace, Friends Of The Earth and Plan B.
The campaigners claimed the Government's National Policy Statement setting out its support for the project failed to properly deal with the impact on air quality, climate change, noise and congestion.
Support from Labour MPs for the expansion helped push through the proposals to expand Europe's busiest airport with a majority of 296 in a Commons vote in June last year.
Mr Grayling said at the time the new runway would set a "clear path to our future as a global nation in the post-Brexit world".
Construction could begin in 2021, with the third runway operational by 2026.