Heathrow third runway may not open until 2039

Heathrow’s third runway may not open until 2039, four years after the government’s 2035 target, under a timetable the airport has set out.

In a statement on 26 September, Heathrow said its focus had “always been to secure planning permission by 2029” and that, once that was achieved, the runway would be open “within a decade”.

Ten years from 2029 would put the opening as late as 2039.

When the government chose Heathrow’s scheme in November 2025, the Department for Transport (DfT) said its policy review would allow a planning decision by 2029 and flights from a new runway by 2035.

“It’s right that ambitious targets were set; the sooner expansion begins, the sooner the whole UK will benefit,” the airport said.

It described expansion as a national project, “100% privately financed”, and put the benefits at “at least 108,000 new jobs” and billions invested in supply chains.

The DfT said there was “currently no live planning application for a third runway” and that it could not comment on ongoing consultation processes or prejudice them “in a way that will only delay progress”.

The timeline had always been ambitious, the department added, and it would keep working at pace with promoters, including Heathrow, and other stakeholders to ensure the right framework was in place for a planning application.

Background

When Heathrow submitted its proposal in August 2025, it said it could deliver an operational third runway for £21bn within a decade.

That depended on the government moving quickly on “necessary policy changes and an appropriate regulatory framework”. The same proposal expected a planning application in 2028.

In advice published on 16 September 2026, the Climate Change Committee (CCC), the independent statutory body that advises the government, said Heathrow expansion was “not currently compatible” with the UK’s net zero target.

What happens next

The DfT’s consultation on the draft Heathrow Expansion National Policy Statement – the planning framework against which any application would be considered – ran from 18 June to 1 September 2026.

In a written statement on 18 June, Transport Secretary Heidi Alexander said any amended version would be laid in Parliament and put to a vote before it had legal effect.

Heathrow had said in January 2026 that Parliament would be asked to decide on the final policy statement in the autumn. The DfT’s response on 26 September gave no date for the vote.

Once the policy review is complete, the government expects Heathrow Airport Limited to apply for development consent, and any application would be examined independently by the Planning Inspectorate.