CAMPAIGNERS urged the UK Government to ditch HS2 last night after it emerged that the project could cost more than £400 million per mile.

Michael Byng, whose method is used by track operator Network Rail to calculate the cost of its schemes, the high speed link could be the most expensive in the world at a cost of up to £104 billion.

The figures come from work commissioned by the Department for Transport (DfT).

It shows the final bill could be double the official figure of £52 billion.

The first phase between Birmingham and London alone could cost the public almost £48bn.

The estimates were revealed in the Sunday Times, with HS2 claiming it “did not recognise” the sums quoted and DfT stating: “We are keeping a tough grip on costs and the project is on time and on budget.”

But last night Joe Rukin, manager of the Stop HS2 campaign, said: “The cost of HS2 has already doubled once since it was first proposed so it should come as no surprise to anyone that it might double again, but when it is the man who wrote the book on estimating rail projects saying this, Government should really listen.

“With it being so obvious to everyone who lives in the real world that there are so many far more important priorities for public spending, it seems utterly insane that the Government are still wedded to this vainglorious vanity project and all its’ false promises.”

He went on: “With the final design for HS2 not due for another 18 months, it is already two years late and that redesign will almost certainly jack up the costs again.

“Since the start, the case for HS2 has been invented by the very cheerleaders who intend to rake in billions of taxpayers’ money which is desperately needed elsewhere, so it really is time to ditch this gigantic white elephant, before it is too late.”

Trains on the new railway will be significantly longer and quicker, with up to 1100 seats per shuttle.

The top speed of 250mph surpasses all express services in Europe and the initial London-West Midlands link is set to be followed by connections with Birmingham, Leeds, the East Midlands and South Yorkshire.

Supporters suggest it could benefit Scotland by £3bn, despite stopping south of the border.

Byng was reportedly asked to look at the figures by “worried” civil servants.

He claims DfT called him for help as it faced a £8.25bn bill for the first 6.6 miles from Euston to Old Oak Common — £1.25bn a mile.

Byng said Michael Hurn, the project sponsor at DfT, is “very worried at the advice he’s been given” from HS2, adding: “The big contractors are also worried. They’ve said when they submit a bid it’s nowhere near the estimates that HS2 have got for the job.”

The revelations come after Chancellor Philip Hammond wrongly put a £32bn price tag on HS2 in a radio interview.

They also follows delays and problems with contractors.

The American engineering company was initially given the lucrative deal to develop the project quit just two months after winning the contract.

In February the UK Government announced US firm CH2M would develop a section of the network from the West Midlands to Yorkshire and Crewe to Manchester.

However, it pulled out in March after “continuing discussions” with HS2 over the contract.