The UK's highest court today (Wednesday 16 December) overruled a judgment made in February that the airport expansion was illegal because it failed to take account of the government's climate change commitments.

Grimshaw had around 100 staff working on the scheme when it was blocked by the Court of Appeal, and was forced to make redundancies.

The practice welcomed news the project is now back on track. Partner Jolyon Brewis said he hoped it helped to 'give confidence to UK airports to build towards a more sustainable future'.

The team behind Heathrow can now apply for planning permission and the practice added that it was 'ready to help design this future when required'.

However major obstacles still remain. These include the drop-off in air traffic passengers during the coronavirus pandemic and the government's adoption of new climate change targets.

The government will get to make a final decision on whether to allow the project after completion of the planning process, which will include a full planning inquiry.

Prime minister Boris Johnson has long opposed the expansion, which would see increased air traffic over his west London constituency. He once vowed to 'lie down' in front of bulldozers to stop the project.

Butin a statement after the ruling, the airport said the expansion remained a vital part of its plans. A spokesperson called the decision to lift the ban 'the right result for the country'.