Theresa May's infrastructure tsar has suggested a "stupid" Tory minister should resign after he himself quit in a bridge-burning blaze of glory.

Lord Adonis - who dramatically left his role on Friday - today slammed Transport Secretary Chris Grayling over a taxpayer-funded "bailout" for the London to Edinburgh rail line.

Virgin Trains East Coast, a partnership between Stagecoach and Sir Richard Branson's empire, has been allowed to walk away from its franchise three years early after the line hit financial difficulties.

That means it is widely expected to pay the government hundreds of millions of pounds less than the £3.3bn it originally promised to run the service.

Stagecoach shares jumped 12% on the news and Labour accused Mr Grayling of being "tough on everyone except the private sector".

Today Lord Adonis said Mr Grayling should quit over the row, telling the Observer: "Handing a cheque worth hundreds of millions of pounds to Richard Branson and Brian Souter [chair of Stagecoach] would be indefensible at the best of times.

Transport Secretary Chris Grayling is letting two firms walk away from a rail deal early
Virgin Trains East Coast, a joint venture between Stagecoach and Virgin, ends early

"But we are now at the worst of times with a Brexit queeze on the public finances and rail fares going through the roof.

"The cost of this bailout is going to be a slashing of the national infrastructure programme and even bigger fare rises.

"As that becomes apparent in Parliament and in the media I think Chris Grayling's position is going to become untenable."

The Labour peer added to the Mail on Sunday: "By his sheer stupidity, Chris Grayling has done more than Jeremy Corbyn and Karl Marx combined to advance the cause of renationalising the railways."

The East Coast line will instead be run by a public-private partnership from 2020. This should involve fees paid to the government but it is not known how they will compare to what was promised before.

Oddly, the Department for Transport said Virgin and Stagecoach "will continue to meet its financial commitments" despite its own minister being the one to announce the commitment will end in 2020 not 2023.

A spokesman said last night: "No-one is getting a bailout and Virgin Stagecoach will continue to meet its financial commitments made on the East Coast rail franchise to the taxpayer as it has done since 2015.

"Stagecoach has also - on average - paid 20% more back to the taxpayer than when the line was operated by Directly Operated Rail and we continue to receive hundreds of millions of pounds.

Sir Richard Branson is the founder and face of the Virgin empire

"The decision to bring in a partnership to run the service from 2020 is to ensure the train companies work more closely with those responsible for the infrastructure, like the track and signalling, to help improve the service for passengers."

Lord Adonis quit in protest on Friday claiming the Prime Minister had sided with Ukip and the "Tory hard right'' over her Brexit plans.

Mr Grayling remains in the Cabinet despite a string of his flagship policies having to be thrown on the scrapheap.

He was Justice Secretary for less than three years yet his prisoner book ban, court fees and a training deal with Saudi Arabia have all been ditched.

A £23m prisoner tracking scheme he unveiled was also axed, while the Court of Appeal slammed a legal aid cut that forced domestic violence victims to show evidence to get a lawyer.