RAIL services could face 'significant disruption' after signalmen said they would refuse to work any overtime for two weeks amid claims a colleague from Swindon was unjustly dismissed, a union has announced.

The RMT union has been in discussion with Network Rail over the dismissal of Swindon signalman Tony Rayner, who they believe has been unfairly sacked.

But on Friday, the union announced discussions to rectify the situation had proved unsuccessful.

Now the signalling staff at Swindon A and Thames Valley Signalling Centres are being urged not to work any overtime between Monday, September 14 and Friday, September 18, and from Monday to Friday the following week.

Network Rail has said the industrial action could cause 'significant disruption' to passengers and has said it remains open to further talks with the union.

Writing to members RMT general secretary Mick Cash said: “Once again I thank you for your magnificent support for your colleague Tony Rayner who we believe has been unfairly sacked by Network Rail.

“Since the overwhelming ballot result, and following our calling industrial action, management requested a meeting to try to resolve the dispute.

"As an act of good faith we suspended the planned overtime ban to allow the meeting to take place and from the outset we repeated our demand for the immediate reinstatement of Brother Rayner.

“Regrettably I must advise you that our meeting with management has proved unsuccessful."

He added: “I urge RMT signalling members at Thames Valley and Swindon to support your sacked colleague who we believe has been unjustly dismissed by Network Rail on unproven grounds.

"We must not tolerate members being treated in this way so I urge you to stand shoulder to shoulder with your colleagues during the overtime ban.”

But Patrick Hallgate, Network Rail’s managing director for the Western route, said Network Rail remained open to talks with the union to resolve the matter.

He said: “Network Rail does not take the decision to dismiss any employee lightly. The individual concerned was dismissed following a thorough and fair investigation and the decision to dismiss was upheld on appeal.

“We are disappointed that we are in this situation and that RMT members are willing to cause significant disruption to passengers as a result of the dismissal.

“We have been engaging with the RMT to seek to avoid this action so that passengers are not disrupted, and we remain open to talks with the RMT should they wish to work with us to resolve this matter.”

The action comes after two separate strikes staged by members of the RMT union employed by train operator First Great Western over two weekends at the end of August amid a dispute over the introduction of new high speed trains.