Train drivers are to be balloted for strikes in protest at a colleague being disciplined for taking a day off work to watch a football match.

Aslef said 1100 of its members at ScotRail will vote in the next few weeks on whether to launch a campaign of industrial action in support of the driver, who reported in sick when he was in Germany watching Rangers play a friendly last year.

The union said he has since been demoted, suffering a pay cut of almost £20,000.

General secretary Mick Whelan said the demotion was "completely unjust", adding: "It means that this driver will be fined almost £20,000 for each year he remains working for the company. As he is 47, this means over £300,000, and because it affects his pension it will go on beyond his working life.

"Compare this to the case in Suffolk where the driver of an uninsured car was fined £265 after killing a 15-year-old-girl, or the speeding taxi driver in Manchester fined £250 after killing a 20-year-old student.

"There's a maximum fine of £2500 for cycling dangerously, even when that has killed. Compared with these cases, this punishment for one unwise sickie in 21 years of working on the railway is deeply, deeply unfair.

"That is why the driver has the full backing of Aslef."

The result of the industrial action ballot will be announced on February 16.

A ScotRail spokesman said: "The driver’s deliberate failure to attend work meant trains were cancelled. That is unacceptable - to our customers, who want a reliable service, and to the company.

"It is deeply disappointing that our passengers could be made to suffer, yet again. We have sent out a strong message that such behaviour will not be tolerated.

"Our drivers are now under pressure from union officials to defend the indefensible. It is to be hoped they will ignore the rhetoric and that common sense will prevail."