The airport operator said it was ready to start design and supply chain activity this year, but needs a swift policy signal and regulatory framework from Government to stay on track.

The airport’s detailed blueprint, published today, sets out how the money will be spent over multiple decades, with £21bn earmarked for the new 3,500m runway and airfield infrastructure, forming the first phase of delivery.

This figure is up from £14bn in 2018, largely due to construction inflation, and includes land acquisition, realignment of the M25 on top of  runway and taxiway construction.

M25 will be rerouted to run beneath the third runway

Alongside the £21bn runway build, Heathrow plans to spend in the longer term

£12bn for new terminal and stand capacity

• Construction of a new “T5X” terminal alongside Terminal 5

• T5X to serve as a second “front door” for passengers with new public transport interchange

• Delivery of T5XN – a satellite terminal near the third runway, linked by track transit

• Additional airside aprons, stands, baggage systems, and connectivity infrastructure

£15bn for airport-wide modernisation

• Major redevelopment of Terminal 2, including two satellite piers

• Phased closure and demolition of Terminal 3

• Refurbishment of existing infrastructure, including the Central Terminal Area

• Public realm upgrades and supporting works

If ministers provide regulatory feedback by September, Heathrow aims to begin design, mobilisation and early procurement activity this year.

Formal community and stakeholder consultation would take place next year for a full planning application to be submitted in 2028 for approval in 2029.

Heathrow CEO Thomas Woldbye said: “It has never been more important or urgent to expand Heathrow. We are effectively operating at capacity to the detriment of trade and connectivity.

“With a green light from Government and the correct policy support underpinned by a fit for purpose regulatory model, we are ready to mobilise and start investing this year in our supply chain across the country. We are uniquely placed to do this for the country; it is time to clear the way for take-off.”

The timing of Heathrow’s submission follows the arrival of a rival expansion plan just 24 hours earlier, as the Arora Group and Bechtel submitted their “Heathrow West” proposal — a lower-cost alternative promising to avoid the need to build over the M25.

That bid aims to deliver a competing Terminal 6 and runway configuration, accelerating delivery and cutting environmental impact.

Both projects now await Government feedback as ministers weigh the future of UK aviation and its global competitiveness.