The High Court has dismissed a district council's attempt to quash a plan to expand Stansted Airport.
Uttlesford District Council hoped judges would block Stansted Airport's plan to accommodate eight million extra passengers each year.
But the High Court has declined to review the plans, while Stansted Airport claims the district council has been "misled by environmental assertions".
Politicians across the council have shared their disappointment at the result.
A Stansted Airport spokesperson said: "We welcome the decision by the High Court and the unambiguous clarity and certainty it provides on the thoroughness of the Public Inquiry process and the strength of our application.
"It was regrettable that UDC allowed itself to be misled by environmental assertions that were not based in fact.
"The High Court’s dismissal of this latest reckless move from UDC means we can now get back to focusing fully on our vision for Stansted, continuing our hard work to recover following the devastating effects of the pandemic."
The airport hopes to build nine new aircraft stands and two taxiway links to accommodate up to 43 million passengers per year, up from the current capacity of 35 million passengers.
District councillors tried to block the plans at a council meeting, but the government's Planning Inspectorate overturned their decision in May 2021, giving the airport the green light for expansion.
The Planning Inspectorate said UDC must foot the airport's appeal bill.
UDC lawyers applied to the High Court in a bid to overturn the decision, claiming inspectors adopted a "blinkered" approach to new carbon budget laws.
They said the inspectors failed to consider Carbon Budget Six which will include international aviation emissions in the government's "net zero by 2050" target for the first time.
A UDC spokesperson said the council was "disappointed" that it could not secure a review on this basis.
They said: "We will carefully consider the implications and advise our councillors on options over the coming days.
"The council will continue to act in the best interests of the district and its residents."
A spokesperson for the party in control of UDC, Residents for Uttlesford, criticised the government's attitude towards aviation expansion.
An R4U spokesperson said: "By allowing yet more huge increases in carbon emissions rather than reductions, the government has shown a very serious dereliction of duty.
"Stansted Airport, while a good local employer, also has to bear the significant responsibilities of any growth."
The airport claims that it is the largest single-site employer in the East of England with 10,200 employees across 200 countries.
The R4U spokesperson added: "The airport has increased 35-fold in size since 1990, which smashes jumbo jet-sized holes in Carbon Budget Six."
The two largest political opposition groups at UDC have criticised R4U's handling of the appeal.
Councillor Melvin Caton, leader of the Uttlesford Liberal Democrat group, said: "I am certain that when people voted for R4U in 2019 they did not expect to end up with the worst of all worlds - an expanded airport and costs approaching £2 million."
Cllr Chris Criscione, leader of the Uttlesford Conservatives group, said: "This administration tried playing politics with the planning system, bodged their attempt and now look to blame anyone but themselves for their failure.
"A Conservative administration would work with the district’s largest employer, supporting jobs in a way that impacts communities around the airport as little as possible."
Stansted Airport Watch (SAW), a group which incorporates Stop Stansted Expansion, said UDC's position has been "confusing".
SAW chair Brian Ross said: "UDC’s position on this planning application has been totally confusing from start to finish.
"From one month to the next you would never be quite sure whether UDC was supporting the application or opposing it.
"It was this inconsistency which resulted in UDC being ordered to pay the airport's costs."
UDC can attempt to appeal the High Court's decision, something which SAW said it would support.
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