The union believes that, behind the scenes, the department’s franchising director Peter Wilkinson is pulling the strings to prevent a settlement of the dispute.

Mr Wilkinson has been quoted as saying he was determined to have a “punch-up” with rail unions, insisting we must “break them” at a public meeting in Croydon in February.

But later yesterday the company caved in.

Labour’s shadow secretary of state for transport Andy McDonald said: “The basis for an agreement is there and I urge a resolution to the dispute that recognises the importance of keeping our railways safe and properly staffed.

“The government’s priority should be addressing the miserable failure of GTR (Govia Thameslink Railway) to run an acceptable service — not picking a fight with staff at the expense of commuters.

“Even if the dispute is resolved today, the UK’s most economically important rail franchise will still be failing passengers who are suffering sky-high fares and the worst delays in the country.

“If the secretary of state is serious about sorting out the mess on Southern, he should be looking to strip GTR of its franchise and run services in the public sector.”

Strike action by RMT Eurostar train managers starts at midnight tonight until midnight on Monday, and a three-day strike is planned for the bank holiday weekend. The TSSA rail union announced that its train managers on Eurostar will strike on Sunday and Monday and for two days of the bank holiday weekend in the same dispute.

General secretary Manuel Cortes said there was still a “window of opportunity” to solve the dispute in talks with Eurostar management on Friday.

But the crisis hitting Britain’s privatised rail industry continues unabated.

Staff on Virgin East Coast, which operates intercity services between London and Edinburgh, have voted by 84 per cent for strike action in a dispute over jobs, working conditions and safety.

East Coast was taken into public ownership in 2009 after privateer National Express abandoned its failing franchise.

During five years of public ownership it made more than £1 billion for the taxpayer. The government then reprivatised it.

Mr McDonald said: “The example of East Coast Mainline demonstrated clearly the benefits of a publicly owned railway: better services, improved industrial relations, investing profits back into the service and returning over £1bn to the taxpayer.

ScotRail was hit by strike action recently as workers resisted bosses’ attempts to sack guards. Management finally agreed to maintain guards on its new train fleet. Disputes are building up at Northern and Merseyrail over the same issue.