The leader of a trade union which represents railway workers has launched a stinging attack on Scotland’s transport minister Michael Matheson, accusing him of being “noticeably quiet” over an SNP commitment to come up with a public sector bid to run trains.

Manuel Cortes, who heads up the TSSA (Transport Salaried Staffs' Association), also criticised the current operator Abellio ScotRail after figures released this month showed one in seven trains arrived late in June and July.

The misery for rail passengers was compounded this week when it was announced that peak fares will rise by 3.2 per cent in January, adding hundreds of pounds to annual commuting costs for many.

Cortes condemned “rip-off fare increases and bargain basement services” and demanded transport minister Michael Matheson “comes clean” about plans for ScotRail’s future.

Matheson’s predecessor Humza Yousaf revealed in the Sunday Herald last July that civil servants would prepare a public sector bid which could take over Scotland’s railways when the current franchise ends.

Dutch firm Abellio ScotRail won the contract in 2015. The 10-year deal worth up to £6bn has a cancellation option at the halfway point if performance is poor.

Speaking to the Sunday Herald in July 2017, Yousaf said the SNP would deliver on its 2016 manifesto pledge to ensure a public sector bidder is in place in 2025, a commitment underlined by an SNP spokesman last night.

Yousaf said: "We have narrowed down the possible vehicles that could potentially take forward a public sector bid. Transport Scotland are now working on gathering further evidence and I will narrow down the options further once that exercise is complete.”

Yousaf later told railway unions he would make an announcement in January 2018, however eight months later there has been no announcement, and Cortes said new transport Minister Matheson has been “noticeably quiet since he took office”.

“Under Humza Yousaf it was all jam tomorrow, with hints of a public sector bidder for the next franchise contest,” said Cortes. “We’re not even getting that from Matheson.

“Our union's position will always be that we must do the right thing for Scottish passengers and taxpayers. That's why ScotRail should be owned by the Scottish people and run in the interests of passengers not greedy shareholders.

“The franchising process wastes millions of pounds of public money every time there is a contest. And as we’ve seen with Abellio, it doesn’t guarantee a quality service.

“But at least Yousaf was willing to have his civil servants work on a public sector bidder. It looks like the Scottish Government are now trying to roll back on that and hoping we’ll forget about it. That’s not going to happen. This was an SNP manifesto commitment and we intend to make sure they keep their promise to voters.”

A report the TSSA published jointly with think tank Common Weal last year showed that ScotRail would run more effectively, and more cheaply, if it was in public ownership.

According to the report passengers could see ticket prices drop by 6.5 percent if there was reinvestment of operating profits, with further savings achievable by ending the franchise system and direct purchase of rolling stock.

It was announced this week that peak fares will increase by 3.2% next year, mirroring the retail price index (RPI) rate of inflation.

Meanwhile, figures released by Abellio Scotrail at the beginning of August showed punctuality in the four weeks to July 21 2018 was 85.5 per cent, the lowest for that period since 2001. In the same period last year, the figure was 93.7 per cent, with Scotrail blaming high temperatures and signalling faults.

TSSA leader Manuel Cortes said “For the amount Scottish passengers, particularly commuters, are shelling out, the very least they could expect is a punctual service. But instead they’re seeing rip-off fare increases and bargain basement services.”

He added: “The insanity of franchising is summed up by the fact that the Dutch national railway runs ScotRail. They make a profit here which they can use to investment in better rail services in Holland whilst Scotland is about to get 40-year-old museum piece trains for its new fleet.

“So much for the SNP standing up for Scotland. Scottish taxpayers, and commuters deserve far better.”

An SNP spokesman said: “We are already working to deliver on our manifesto commitment to ensure a robust public sector bid for future rail franchises.”

Transport minister Michael Matheson was not available, but a Transport Scotland spokeswoman said: “In line with the Programme for Government Commitment, we are progressing with plans to enable a competitive public sector bid. An update will be provided shortly, followed by a further meeting of the Public Sector Bidder stakeholder reference group to which all transport spokespersons and key stakeholders, such as trade unions, are invited.”

She added: “We should not lose sight of the transformational process underway on our railways including the infrastructure enhancements, as well as the introduction of new and fully re-furbished rolling stock with the additional services that they will provide. All this is building the best railway Scotland has ever had and with that overall performance should improve moving forward.”