However, the push for economic growth and promises to cut regulations have led some to question whether this is being prioritised over environmental concerns.
One former Labour frontbencher suggested the chancellor was in danger of looking “desperate” in her search for growth.
The expansion of Heathrow has long been opposed by green groups and some Labour MPs and residents living near the airport.
Sir Keir Starmer and seven ministers who attend his cabinet – including Energy Secretary Ed Miliband and Environment Secretary Steve Reed – voted against proposals for a third runway in 2018, when the party was in opposition.
London mayor Khan has said his opposition to a third runway has not changed and he would support a legal challenge if the government backed proposals.
There is currently no application for a third runway at Heathrow and in December the airport’s boss said the company needed a “clear steer” from the government by the end of 2025 for plans to be taken forward.
