The High Court in London has ruled that a third runway at Heathrow should go ahead.
Construction of the third runway at one of the world's busiest airports is scheduled to begin within two years, with completion set for 2026.
Judges had heard five separate challenges to the proposed expansion from a group of local councils, residents, environmental charities and Mayor of London Sadiq Khan. But on Wednesday, three High Court judges ruled in favor of the plan.
The U.K. government said in 2018 that additional capacity at the airport is "in the national interest and based on detailed evidence." A majority of 296 lawmakers in the U.K. Parliament backed the plan last year.
But campaigners have argued that the U.K. government's decision to build the additional runway failed to address the impact on air quality, noise, and local traffic congestion.
One claimant, an environmental action group called Plan B, had also argued in its case documentation that by building an extra runway the U.K. government was contradicting its commitment to the Paris Agreement on climate change.
This agreement, signed by a number of countries in 2016, offers a commitment to mitigate greenhouse-gas emissions. In 2017, President Donald Trump said he will withdraw the U.S. from the agreement.
Tim Crosland, Director of Plan B and a legal adviser to another climate action group Extinction Rebellion, called the judgement "disappointing" and it was hard to see how lawmakers could proceed.
"Following the recent Extinction Rebellion protests there is widespread recognition that we are in a state of climate and ecological emergency," he said in a statement.