Andy Burnham should consider taking a stake in Heathrow to keep its planned £49bn third runway under control, the owner of British Airways (BA) has said.
Luis Gallego, the chief executive of BA owner International Airlines Group, said state involvement in Heathrow may be necessary to make the project affordable for passengers.
Airlines have baulked at Heathrow's bill for expansion, which they claim would require the airport to more than double fees paid by passengers from £26 to £65.
Mr Gallego said that the Government taking a stake could be the most effective route to delivering the runway at an affordable price.
He told The Telegraph: "There is an option that the Government can be involved in order not to duplicate the charges to the passengers.
"If we can reduce the cost of the project, that's the mission."
The calls from BA come amid growing uncertainty over the future of Heathrow's third runway. Last month, it emerged the expansion is likely to be delayed by four years until 2039 after the timeline promised by Rachel Reeves, the former chancellor, was branded "unrealistic".
Meanwhile, the Prime Minister's commitment to the third runway is becoming increasingly at risk, with The Sunday Times reporting Mr Burnham was "unconvinced" by the need for expansion.
He repeatedly refused to back the scheme during the Labour conference in Liverpool, describing it as a "contested issue" and one in which views of residents of the capital should be taken "seriously" when reaching a decision.
Mr Gallego said: "I think this is not a question of London. It's a question of the UK economy, of growth, of employment and competitiveness against other European hubs.
"Heathrow is the only hub that we have in the UK and we need to develop the hub in order to have connectivity for all of the UK."
According to a survey of 2,000 respondents commissioned by BA, more than 60pc of Britons back the third runway, rising to almost 70pc of Londoners.
The survey, carried out by JL Partners, also found 57pc of voters backed the Government taking a stake in Heathrow's expansion, with approval strongest among Labour supporters. Just over one in 10 respondents were against the plans.
Half of respondents said Heathrow's existing shareholders should foot the bill for the runway, with only 6pc agreeing that it should be funded by passengers through higher fares and 3pc saying it should be paid for by taxpayers.
Mr Gallego said there were a range of funding models to explore beyond the current passenger fee-based charging system.
He added: "I think there are different ways if this [a government stake] is the conclusion. For example, if we have more passengers, we are going to generate more revenues that we would not have if we don't develop the airport.
"We need to think how these revenues could help the development of the airport and that's something we can explore."
While public-private partnerships for the development of runways and terminals are common, how the Government would secure a stake is unclear.
Heathrow has been in private hands since 1987 and is currently owned by the sovereign wealth funds of Qatar, Saudi Arabia, Singapore and China, together with a French private equity firm and an Australian pension fund.
The Prime Minister has promised greater "public control" of Britain's essential services.
Labour is nationalising the railways and bus fleets and has taken control of British Steel, while Mr Burnham has taken steps to bring water utilities under public ownership and establish a state power-grid company.
Heathrow declined to comment.
