Under current rules, the number of domestic flights from Heathrow is limited in order that other EU destinations are fairly served.
Heathrow has championed for many months the fact that it is the UK's main port and front door for international visitors. And it said that an exit from the EU provided a opportunity to do-away with domestic flight restrictions, open up new routes and provide Britain's cities better access to international travellers and trade.
Liverpool is one such city that has been starved of access to Heathrow.
“Heathrow is the UK’s hub airport. A route there would enable Liverpool to have onward connections to every continent of the globe as well as easy access to London. Liverpool has missed out on this link for over 24 years, said Andrew Cornish, the chief executive Liverpool's John Lennon Airport.
Reports surfaced overnight that Theresa May has sufficient parliamentary backing to rubber-stamp plans for a third runway at Heathrow.
And Britain's largest airport said that it could squeeze out another 25,000 flights a year using its current two runways if it gets the green light from the government to build a third.
"The Prime Minister and the government can now to make the right choice, and back Heathrow expansion," said Heathrow chief executive John Holland-Kaye.
Although the airport is subject to a cap on the number of flights taking-off and landing, it believes that it could "tweak" its schedule to increase capacity. Any such changes would require sign-off from the government and Heathrow said it wouldn't be willing to consider these unless it received assurances that its expansion plans would be approved.
"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," said Holland-Kaye.