Third class rail travel could be a possibility under a private-owned East Coast Main Line (ECML).
This was uncovered by the National Union of Rail, Maritime and Transport Workers (RMT), despite denial from the government when it previously leaked the information two weeks ago.
RMT is against the privatisation of ECML - it is one of the last few services provided by Directly Operated Railways (DOR), the Department for Transport's holding company, and has earned around £600 million in profits since it came back under state control.
RMT general secretary Bob Crow said: "As well as turning the clock back more than 50 years this government is also happy to write off a billion pounds of returns to the taxpayer from publicly-owned DOR and smash apart the most successful rail franchise in Britain."
Mr Crow argues denationalising the service and allowing a third rate ticket would encourage foreign investors to invest in the line to fund their own services, taking money away from the UK's rail transport.
The call for state rail was also backed by Unite after it published a report on transport strategy yesterday (November 11th). In the document, the union pushes for bringing rail back into public ownership.