A row has erupted over who will pay for pledged free travel for season ticket holders as compensation for ScotRail train delays.
MSPs were angered after the train operator said it had yet to agree to contribute to the £3 million scheme to offer a free week for passengers with monthly and annual passes.
They accused transport minister Humza Yousaf of making the announcement last month after calculating the plan “on the back of a fag packet”.
ScotRail managing director Phil Verster said it would involve the train operator contributing £1.8m from a fund for rail improvements.
However, he told Holyrood’s rural economy and connectivity committee that ScotRail had only been given a few weeks’ notice before the announcement, and was still considering it.
The contribution would come from a fund generated by fines for ScotRail failing quality checks under the Service Quality Incentive Regime (Squire).
Improvements due to be payed for from this fund include toilets at Tweedbank Station at the southern end of the Borders Railway.
Rhoda Grant, a Labour member of the committee, said: “It is increasingly clear Humza Yousaf’s announcement was calculated on the back of a fag packet, and even that might be too kind a description.
“The fact that ScotRail still don’t know how they will pay for the SNP’s plan is astonishing. This is yet another example of too much spin and not enough substance from Humza Yousaf.”
Liberal Democrat transport spokesman Mike Rumbles said: “Passengers were told this free week came courtesy of the generosity of the Scottish Government.
“Instead, we find out today it is being funded by a raid on the fund for rail improvements.
“This is a scandalous and fraudulent move by the Scottish Government and passengers deserve so much better.”
The Scottish Government said it remained “absolutely committed” to the offer.
A spokesman said: “A free week’s travel will be offered this year and further discounts for daily, weekly and leisure travellers.
“The ScotRail contract permits Squire funding to be directed to initiatives that improve the customer service experience, and we are currently negotiating the terms of the fares initiative with ScotRail through Transport Scotland, with the details expected to be finalised and announced in the coming weeks.”