ScotRail operator Abellio was handed more than £200million in pandemic aid in the year before a decision to nationalise the service.
The Scottish Government revealed last week it will form an arm’s-length company to replace the train firm in spring next year.
Between March and September 2020 ministers handed Abellio – which is owned by the Dutch state – £215.3million over and above its normal franchise payments.
And while the cost of keeping services rolling over the last six months in the face of Covid-19 has yet to be calculated, payments are likely to run into hundreds of millions more.
Scottish Labour transport spokesman Alex Rowley said taxpayers were being forced to foot the bill for political ineptitude.
He added: “The decisions made by the SNP Government on railways over the last decade have brought us to the current situation.
“Not only was the franchise arrangement left in disarray, the SNP continued to pour our money into a failing system and then bailed Abellio out with even more cash.
“What will really anger people is that part of the bill is millions in so-called management fees to the firms. This failure has come at a staggering cost to taxpayers and rail users.
“An operator of last resort is finally a step in the right direction but what is really needed is a reliable, cost-effective public transport system.”
Abellio has been running Scotland’s railways since 2015 but has faced heavy criticism over performance.
It was announced last week that a public sector body will take over from the end of March next year.
Transport Scotland said: “Abellio ScotRail was allocated £215.3million of additional funding between March and September 2020, which allowed rail services to continue for key workers and provide job security for rail employees.
“This payment is in addition to the regular franchise payments.
“The cost of running ScotRail through Scottish Ministers’ Operator of Last Resort function will be comparable with the costs evident through the current emergency measures agreement, where cost and revenue risks are borne by the Scottish Government.
“The costs from September onwards will not be known until a full financial reconciliation has taken place.”
However, a source said:“The £215million of emergency funding is for the six months between March and September last year.
“It wouldn’t be wrong to assume that the period between September and now will have required similar sums so the running total could be close to half a billion.”
All ScotRail staff will transfer to the new Scottish Government-owned entity.
Transport Secretary Michael Matheson refused to say how long the “operator of last resort” arrangements will last, while calling Abellio’s time in charge “a difficult period”.
He has called the franchise system “broken” and “not working in the taxpayers’ interest”.
Tory MSP Graham Simpson said: “The SNP’s track record in running transport services is appalling.
“You only need to look at our ageing and unreliable ferry fleet, with new ones not built and massively over-budget, to see what can happen.”
The RMT union said public ownership will deliver benefits for rail workers, passengers and taxpayers.
The UK Government runs the East Coast franchise through its arm’s-length LNER company.
A ScotRail Abellio spokesman said: “Passenger numbers are down more than 90 per cent compared to before the pandemic.
“The Scottish Government’s emergency support has enabled ScotRail to maintain safe and reliable services for key workers, pay the wages of our 5200 staff and now support the vaccine roll-out.
“We’re working flat out to get ready to welcome passengers back to the railway when restrictions allow.”
