Labour ministers have reportedly selected the most expensive proposals to expand Heathrow airport and add a third runway to the country’s central flight hub. The Department for Transport has backed the proposal set to cost the country £49 billion, which requires moving part of the M25 motorway.

The move saw a cheaper proposal, estimated at around £23 billion, get passed over. It would have had a shorter runway and avoid the need to move the main London orbital ring road. Ministers at the department opted for the more expensive option, despite opposition from top airlines such as BA and Virgin. Earlier this month, BA CEO Sean Doyle warned ministers to “avoid moving the M25” as part of the expansion plans.

Mr Doyle added: “I think we should look at ways of potentially building a shorter runway.

“I can’t argue against the logic of that. I think we should look at ways of potentially building a shorter runway.”

Aviation analyst Robert Boyle has also suggested that the present case for building the longer, full-sized runway is no longer as strong due to newer “narrow body” aircraft being able to fly longer distances.

Around 98% of the flights that departed Heathrow last year would have been able to do so with the shorter 2,800m runway proposal.

Mr Boyle said: “If the third runway was being built in a desert you would probably build it longer for maximum operational flexibility, as the cost of a bit more concrete isn’t that big. But when the cost of accommodating a longer runway is having to divert a 12-lane motorway and meddle with one of the most complicated and busiest motorway junctions in Europe, you surely need a really compelling reason to do so, which I don’t see.”

Airlines are now warning that the spiralling costs of the expansion project will have to be funded through higher landing charges, which could be passed on to customers.

The Transport Secretary Heidi Alexander, is set to confirm the Government’s decision tomorrow.

However, according to the Financial Times, she will leave the possibility open for other companies to build and operate terminals at the airport.

The expansion was announced by Rachel Reeves as part of her desperate efforts to boost economic growth.

Sir Keir Starmer said adding a third runway “gives us the chance to reduce the risk of flight delays, to open competition [and] to lower fares,”

“I strongly believe they have ducked decisions for far too long. The third runway at Heathrow has been the decision that has been dumped and delayed for decades.”

The Department for Transport has refused to comment on speculation ahead of tomorrow’s announcement.