A final verdict on Heathrow’s third runway is due to be handed down this week.
The Supreme Court is to rule on Wednesday on the long-running saga over expansion of the London hub.
The £14 billion project was blocked by the Court of Appeal in March when judges ruled that ministers had failed to take into account climate change commitments.
Heathrow appealed to the Supreme Court at a hearing held over two days in October.
Local councils and environmental groups such as Friends of the Earth have long lobbied against the third runway plans.
Heathrow has argued that the additional runway is still needed to accommodate future growth despite a near collapse in airline travel during the Covid-19 pandemic.
The airport revealed last week that Terminal 4 would remain closed until the end of 2021 following an 88% slump in November traffic during England’s second lockdown.
The Supreme Court will consider whether the government’s failure to take account of the UK’s climate change commitments renders Airports National Policy Statement designation favouring the third runway development unlawful.