Heathrow today re-emphasised its case for a third runway as being key to the UK’s success after Brexit in the face of legal challenges.

The boss of the London hub repeated a warning that rival Paris Charles de Gaulle is poised to overtake Heathrow as Europe’s top airport within two years.

Heathrow plans a further eight-week public consultation between April and June before submitting a final planning application.

This will detail how the airport proposes to expand and connect all of Britain to global growth, while meeting the requirements of the government’s Airports National Policy Statement.

“It will also restate our commitment to ensuring an expanded Heathrow meets strict environmental targets, delivers tens of thousands of new high-skilled jobs and honours the commitments the airport has made to local communities,” the airport said.

However, Heathrow faces a Court of Appeal judgement on a judicial review over MPs backing expansion.

“We remain of the view that a robust process has been applied to date, including the extensive evidence gathered by the independent Airports Commission, multiple rounds of public consultation and the overwhelming vote in Parliament,” Heathrow said.

“If the appeal were to go against the secretary of state for transport, depending on the detail of the judgement, we will carefully consider our next course of action.”

But the airport concluded that expansion “is probable”.

Chief executive John Holland-Kaye called for action on expansion as Heathrow reported a rise in annual pre-tax profits of more than £100 million to £375 million for 2019 as passenger numbers edged up by 1% to 80.9 million – the ninth consecutive year of growth.

Load factors increased to a record 80% but one in five seats remain empty, which provides a “significant growth opportunity” prior to expansion.

The average number of seats per aircraft also increased to 213.7, driven by upgrades on European and Middle Eastern routes.

Long-haul traffic grew by 2.2%, driven by transatlantic services with increased load factors and frequencies, and new routes such as Pittsburgh and Charleston.

Africa traffic also grew strongly due to additional services to Marrakesh, Seychelles, Durban and Johannesburg.

Middle East traffic increased due to larger aircraft and improved load factors.

Asia Pacific traffic dropped due to the collapse of Indian carrier Jet Airways.

Short-haul traffic declined slightly by 0.3% with a number of carriers reducing European services.

Domestic traffic grew 0.9% with new routes to Newquay, Guernsey and Isle of Man.

Holland-Kaye said: “Within two years, Charles de Gaulle will overtake Heathrow as the biggest airport in Europe. Heathrow’s new runway is ready to turn ‘global Britain’ into more than just a campaign slogan.

“It’s the key to the UK’s success after Brexit and will ensure we stay ahead of our European rivals.

“Expansion will be built within legally-binding environmental targets, creating lower airfares for passengers, connecting every corner of Britain to global growth and all at no cost to the taxpayer. It’s time to get on with it.”