He stated he would be keeping 'all options on the table' in response to the proposals, indicating a potential lawsuit against the government.
Chancellor Rachel Reeves has expressed confidence that the expansion will proceed, despite Khan's opposition, emphasising its role in boosting economic growth.
Other senior Labour figures, including Andy Burnham and Ed Miliband, have also voiced opposition to the Heathrow expansion, while London Gatwick has received conditional approval for its own expansion plans.