The UK could lose up to £31 billion (€43bn) in trade by 2030 because of the failure to increase flights to Brazil, Russia, India and China alone, according to research.

Ryanair has opposed recommendations for expansion at London’s Heathrow Airport, saying that the only solution to the airport capacity crisis in the south-east of England lies in more runways at all three of the city’s main hubs.

Britain’s two biggest airports were busier than ever in 2014.

Architects have come up with designs for Heathrow City — a 190,000-home town that would spring up if the west London airport closes.