Andy Burnham has thrown the Heathrow third runway project into doubt by privately telling MPs he has always opposed expansion, while new prime minister Keir Starmer's Labour administration remains "open minded" on the scheme. Sir Keir Starmer's government announced in early 2025 it supported Heathrow's expansion proposal, which requires complex planning processes before construction can begin. One Labour MP revealed Burnham was "highly critical" in a recent private meeting, stating he "never supported Heathrow's expansion" and is awaiting a transport committee report before deciding his position.

Officials say Burnham's mind is open, "listening to MPs and other groups in the meantime". The project has seen fluctuating political support over two decades. Chancellor Rachel Reeves resurrected it last year to boost economic growth, with her successor John Healey stating in January 2025 the government gave approval because "the economic case stacks up and will help bring growth".

Burnham, previously a vocal critic, served as mayor of Greater Manchester opposing the project as diverting infrastructure investment from the North. Heathrow executives are awaiting Burnham's Budget mention next month. Dame Siobhain Mc Donagh, MP for Mitcham and Morden, supports the scheme as "good for the country, good for jobs and apprenticeships".

The Department for Transport published a draft Heathrow Expansion National Policy Statement in June, with Transport Select Committee scrutiny underway ahead of parliamentary approval.