Labour has called on the Scottish Government to back its plans to nationalise the East Coast mainline after early termination of the franchise.
The party's Rural Affairs and Connectivity spokesman Colin Smyth has written to Scottish Transport Secretary Humza Yousaf, urging him to publicly endorse renationalisation for the Edinburgh-London services.
Mr Symth said it was "extremely disappointing" Mr Yousaf had not yet done so but the Transport Secretary said "no options for the future of the East Coast mainline should be taken off the table".
The UK Government has announced that franchise operator Stagecoach would continue running the line for only a few months because of losses.
UK Transport Secretary Chris Grayling has said it could then be allowed to continue to run services on short term non-profit basis or the government may step in to run the service.
In his letter, Mr Smyth wrote: "I am writing to urge you and the Scottish Government to publicly support Labour's calls for the East Coast mainline to be renationalised following the collapse of its franchise.
"The decision by the UK Government to sell-off the franchise to Stagecoach was a betrayal of taxpayers and the travelling public. The failure of the Stagecoach franchise reflects the deep-rooted problems with our privatised railways but we now have an opportunity to put the East Coast mainline back into public hands.
"In the past the Scottish Government have claimed to support publicly-run railways in Scotland, so it is extremely disappointing that so far you have chosen not to support Labour's call for a publicly-run East Coast mainline, particularly given how important these services are to passengers in Scotland."
He added: "This is a highly profitable route, and it is one that thousands of Scots rely on each day. From 2009 to 2015 the route was publicly run, raising more than £1 billion.
"Returning it to public hands would not only ensure the best service for customers, but it would provide a boost to public finances."
Mr Yousaf said: "Both myself and my predecessors have long made clear to the UK Government our preference for public sector operators to be given a fair chance to operate our railways.
"Previous UK administrations - both Conservative and Labour - have repeatedly denied the Scottish Government the powers to allow a public sector body to bid for rail franchises.
"Only now, after repeated efforts, do we have powers to enable future contracts in Scotland to be let to the public sector and we are working to enable a public sector bid for Scotland's railways in the future.
"The UK Government has the contractual relationships with East Coast Rail's operators and they should be held to account for the current situation. Our priority is to ensure continuity of services for travellers.
"No options for the future of the East Coast mainline should be taken off the table, including the UK Government continuing to run the contract and returning the appropriate profits to Scotland."