Heathrow third runway opening pushed back four years to 2039

Heathrow's planned third runway is now not expected to open until 2039. That is four years later than the 2035 date the government set when it backed expansion.

It is understood that airport bosses told the government in late September that the 2035 deadline could not be met. Heathrow says its aim has not changed. It wants to get planning permission by 2029 and open the runway within ten years of that.

A Heathrow spokesperson said: "It's right that ambitious targets were set: the sooner expansion begins, the sooner the whole UK will benefit. Our focus has always been to secure planning permission by 2029. Once achieved, the runway will be open within a decade."

The airport calls the scheme a national project that is 100 per cent privately financed. It says expansion would create at least 108,000 new jobs and bring investment to supply chains across the country.

No planning application yet

The Department for Transport stressed that the scheme is still at an early stage. A spokesperson said: "There is currently no live planning application for a third runway, and we cannot comment on ongoing consultation processes or prejudice them in a way that will only delay progress."

The 2035 date came from Rachel Reeves, then chancellor. In a major speech on infrastructure in January 2025, she announced government support for a third runway. She said it would help grow the economy and create 100,000 jobs.

On 18 June 2026 the government published a draft Heathrow Expansion National Policy Statement. This sets out the planning framework for a new runway but does not itself give permission to build. The public consultation on the draft closed on 1 September.

Heathrow still has to apply to the government for permission to build, through what is called a Development Consent Order. Only then would a full planning decision be made.

What the scheme involves

The expansion is expected to cost about £49 billion in total. Of that, around £21 billion would go on the new runway and its airfield infrastructure, £12 billion on expanding the terminals and £15 billion on modernising the existing terminals. Terminal 3 would close in the longer term.

The plan is for a 3,500-metre runway to the north-west of the current airport. The M25 between junctions 14 and 15 would be rerouted through a tunnel under it. Expansion would allow up to 756,000 flights a year.

The new runway's footprint would fall on villages in the London Borough of Hillingdon, including Harmondsworth and Sipson. People there have lived for years with the threat of homes, roads and green space being lost to expansion. For them, a later date means even longer without knowing what will happen.

Political uncertainty

The delay came out just as Labour's annual conference was opening in Liverpool. In a television interview on Sunday 27 September, Prime Minister Andy Burnham was asked repeatedly whether he supported a third runway and would not say that he did. He described it as a contested issue that had been consulted on.

His predecessor, Sir Keir Starmer, had backed the scheme. The Mayor of London, Sadiq Khan, has long opposed it. Earlier in September the Climate Change Committee, which advises the government, said Heathrow expansion could not go ahead unless the aviation industry is made to cut its emissions.

Unions back the project. GMB London said opponents would try to present the new timetable as a verdict on the scheme as a whole.