Ms Laird said: “This offer – a bit like the trains – is not very accessible.

“In order to take advantage of it you first need to sign up to a MyScotRail account and book your ticket in advance. “

“In addition, ScotRail have confirmed that the normal two Kids Go Free for every paying adult fare is not applicable to the £5 ticket, as it is a promotional offer.

“So not only does this offer apply only for a limited off-peak period, but rail users also can’t simply walk into a station and buy their ticket. 

“This has not been clearly communicated and of course simply fails to address the fundamental issues on the Fife rail service.

“Constituents are fed up with poor service, overcrowded carriages and trains skipping stations. 

“And when you add in paying two and three times more per rail mile than other parts of Scotland, this offer does nothing to address long-standing issues.

“Humza Yousaf committed to me in September 2016 that rail pricing would be reviewed as part of the National Transport Review. Now Transport Scotland, in recent correspondence to me, seem to be rolling back from that commitment. The implication is that Fife must continue to subsidise other low-cost routes. That is simply not acceptable. 

“This is a long-standing issue and will be difficult to address. But Transport Scotland the Minister must stop putting their heads in the sand and face up to fixing a flawed rail fare system. 

“After 10 years in charge, there has been ample time to fix this – but there is clearly a lack of political will to do so.

“Labour is calling for a renationalisation of the rail service so that issues like these can be addressed. The Scottish Government must get off the fence in addressing long-standing rail transport issues and stop the post code lottery on Fife rail fares.”