Heathrow claims to have the potential to expand by adding up to 5% more flights on its existing two runways.

This would allow up to 25,000 additional air traffic movements on the current runways in early 2021, if the London hub is granted government permission for a third runway.

Heathrow could add more flights by reducing gaps between aircraft movements, thus expanding existing capacity before any new runway comes into operation in 2025.

The airport says more flights can be introduced on the existing runways “with no impact to resilience or passenger experience and environmental commitments”.

This would give the UK economy a £1.5 billion ‘Brexit boost’ while a third runway is being built, according to the London hub.

The new proposals are to be detailed on the first day of the upcoming Conservative Party conference and come as the lobbying battle with rival Gatwick intensifies for the right to expand.

The government is not expected to make a final decision about how to proceed until a special aviation sub-committee, chaired by Theresa May, meets on October 11 or 18.

The additional Heathrow flights, derived from new air traffic technology called Enhanced Time Based Separation, would be allocated to routes which would help support export market by connecting UK cities, and markets in Japan, India and China.

Unlocking the additional capacity could give an extra 21 regional or short-haul services – with a potential for seven new routes, three flights a day or additional services for Inverness and Leeds Bradford and six other routes – plus 13 new daily long-haul flights.

New domestic connections could include Newquay, Liverpool, Humberside, Jersey and the Isle of Man.

Examples of the likely new long-haul routes are Quito, Wuhan, Goa, Katmandu, Kochi, and Kansai (Osaka).

To help establish new domestic connections, Heathrow is suggesting an extension of its existing £10 ‘domestic passenger discount’ for all flights to UK airports until 2037, as long as there is justification and it is deemed to be in the public interest. It will also bring forward a £10 million route development fund to 2021.

A £10 million route development fund will support up to five new domestic routes from the point that Heathrow adds new capacity.

An unspecified emissions charge for vehicles travelling to and from Heathrow is being considered to coincide with the start of any new flights, with the money raised going towards funding local public transport improvements

Heathrow chief executive John Holland-Kaye said: “This Brexit boost plan is our commitment to making Britain stronger and fairer for everyone – faster.

“It would generate around £55 billion more in growth than Gatwick in the early years of Brexit.

“Our proposals for an additional 25,000 flights a year from 2021 would help businesses and families from Newquay to Dundee benefit earlier from Heathrow expansion, while protecting our commitment to meet and exceed the Airports Commission’s environmental conditions.

“Heathrow’s third runway is the only option that can help every nation and region of Britain realise the opportunities of Brexit.

“The prime minister and the government can now to make the right choice, and back Heathrow expansion.”