British Prime Minister Andy Burnham has declined to endorse a third runway at London Heathrow Airport (LHR), telling the BBC on September 27, 2026 that the decision belongs first to London and its residents.

Asked directly whether he supported the expansion, Burnham said: "I think principally, it's a matter for London and Londoners."

The prime minister positioned himself firmly behind the public consultation process rather than the project itself. "I think you've got to hear the voice of people there first," he said. "It's not right for me to just jump straight in on the back of the consultation."

He acknowledged that opinion remains divided. "There's a consultation, but there are different views, and you have to take those views seriously in coming to a decision," Burnham added.

The remarks place the prime minister at arm's length from one of the UK's most contested aviation infrastructure projects — and align him, at least rhetorically, with two prominent opponents of expansion. The Mayor of London, Sadiq Khan, is against the third runway. Burnham himself expressed skepticism about the idea when he served as mayor of Manchester.

2035 Deadline in Doubt

Burnham's comments landed amid reports that Heathrow has conceded the current 2035 deadline for the expanded runway will not be met. The airport has not confirmed a revised timeline.

The schedule pressure compounds the political ambiguity. A project already decades in the making now faces a prime minister unwilling to declare support before the formal planning process advances, an opposed London mayor, and a delivery date that appears to be slipping before a planning application has even been submitted.

Consultation Opens in October

On September 28, 2026 — one day after Burnham's interview — Heathrow released details of an eight-week public consultation on its expansion plans. The consultation will run from October 27 to December 22, 2026, giving residents an opportunity to examine the proposals before the airport submits its planning application.

Heathrow moved quickly to frame the prime minister's comments as consistent with its own approach. "We agree with the Prime Minister that local voices must be heard," said Becky Coffin, Heathrow's Director for Communities and Residential Property.

"We know from consistent polling over the last decade that communities support our plans for expansion, and support is only growing over time," Coffin said.

She extended the argument beyond endorsement to participation. "But more than that, we want local people, businesses and education institutions to have genuine opportunities to shape and finalise our plans. This consultation is a chance to do just that."

Political Distance Before a Planning Decision

For airlines and hub-dependent operators at Heathrow, the prime minister's refusal to offer even qualified backing introduces a new variable into a project whose economics depend on political certainty as much as engineering. The government's position — deferring to local opinion until the consultation concludes — leaves the airport to build its case on the ground while the planning clock runs.

Khan's continued opposition, Burnham's own record of skepticism, and the reported failure of the 2035 target together suggest that any capacity relief from a third runway remains years away, whatever the consultation's outcome. The eight-week window closing on December 22 will mark the next concrete test of whether Heathrow can convert decade-long polling support, as the airport characterizes it, into a planning application that survives both local scrutiny and national politics.