The Court of Appeal dismissed a bid by campaigners to challenge a High Court ruling in June that the scheme could proceed.
The development of Gatwick Airport’s second runway is set to begin after the Court of Appeal upheld an earlier ruling that the plans could go ahead.
The £2.2 billion expansion, approved by Transport Secretary Heidi Alexander in September, will see the West Sussex airport move its emergency runway 12 metres north to accommodate around 100,000 more flights a year.
It will allow the site to be used for the departures of narrow-bodied planes such as Airbus A320s and Boeing 737s, with the first flights expected to take off from the new runway from 2030.
Gatwick is the UK’s second busiest airport and one of the busiest single-runway airports in the world.
On Tuesday, the Court of Appeal dismissed a bid by campaigners to challenge a High Court ruling in June that the scheme could proceed.
Mrs Alexander said the decision was a “major milestone for Gatwick and for local communities” which would create thousands of new jobs.
She said: “Around 13 million more passengers and 100,000 more flights will give holidaymakers greater choice and strengthen global links to help make the UK one of the most attractive places in the world to invest.
“We’ll back expansion that supports growth and our climate goals.
“To drive forward sustainable change, we’re also investing over £219m for green fuel production to cut emissions from flying and secure the future of aviation.”
Pierre-Hugues Schmit, the airport’s chief executive, said the latest court ruling “brings to an end an eight-year planning and legal process which has carefully tested and scrutinised every aspect of our expansion plans on multiple occasions”.
He said: “We can now press on with the important job of bringing this exciting project to life and move forward into the design and delivery phase.”
Gatwick Airport previously said that the privately funded scheme is “shovel-ready” and would provide a £1 billion boost to the economy every year.
It also said that there would be “little disruption” to operations at the airport during development as the runway already exists.
Campaigner Peter Barclay and campaign group Communities Against Gatwick Noise Emissions (Cagne) took legal action against the Department for Transport over the decision to approve the plans, telling the High Court in January that the Government did not properly assess the scheme’s climate impact.
But Mr Justice Mould ruled in June that it was “neither illogical nor contradictory” for Mrs Alexander not to refuse the proposed development “on the basis that it would have a material impact on the ability of Government to meet its carbon reduction targets”.
He also rejected an argument about the need for the expansion at Gatwick, given the proximity to Heathrow.
Mr Barclay and Cagne then asked the Court of Appeal to allow them to challenge the ruling last month, claiming that the judge was wrong.
But in a ruling on Tuesday, Lord Justice Holgate and Lord Justice Dove dismissed the appeal bids.
In a 29-page ruling, they said: “We conclude that each of the grounds of appeal raised by each appellant is unarguable.
“Neither appeal has a real prospect of success. We also consider that there are no other compelling reasons for either appeal to be heard.”
The two senior judges also said that Mr Justice Mould’s ruling was “detailed and thorough”.
Following the decision, Cagne said it would “continue holding Gatwick to account”.
It said: “This is a deeply disappointing reflection of a government that is failing to take a balanced approach to airport expansion, particularly where an airport such as Gatwick seeks to export sterling from the UK economy while imposing significant costs on local authorities, communities and the environment.”
