All three global airline alliances have said they want to stay at Heathrow, bolstering the chances of a third runway being built at Europe’s busiest hub.

British Airways has emphasised its wish to remain at Heathrow, and the Oneworld alliance – which is led by the UK flag carrier – said its commitment to the hub reflected the airline’s view.

Star, which includes Lufthansa, United Airlines and Sinagpore Airlines, is the second-largest alliance at Heathrow after Oneworld and pointed out that its member carriers planned to move into the hub’s new Terminal 2 next year.

“This will allow us to effectively compete with the other alliances in Heathrow and add to the quality of our services and therefore we do not see any opportunity for us to make a change to another airport,” it added.

SkyTeam, which includes Air France-KLM, Delta Air Lines and China Eastern, said Heathrow was of “utmost importance” to the alliance.

“Relocating to another London or UK airport is not an option for our members,” said Tae Joon Kim, SkyTeam’s vice-president of airport services in a letter to the government’s Airports Commission.

Insiders at Star and SkyTeam said the only circumstances in which they might consider moving from Heathrow would be if all three alliances were to relocate together to a new hub, the Financial Times reports today.

However, they echoed Willie Walsh, chief executive of BA parent company International Airlines Group, who has expressed strong doubts about how a new hub could be financed.

London mayor Boris Johnson is proposing a four-runway airport in the Thames estuary, to cost the taxpayer at least £25 billion, while Gatwick has suggested that it could turn itself into a hub if it gets permission to build a second runway.

Gatwick opposes Heathrow’s expansion and is interested in persuading one of the airline alliances to move there.