HUNDREDS of ScotRail services have been cancelled due to a driver shortage linked with an ongoing pay dispute just as the company has launched a new timetable.
ScotRail apologised to customers for the disruption to around 300 services on Sunday after 110 were affected last weekend.
Since last week, Aslef has balloted its members for strike action after rejecting a 2.2% pay offer.
The union said it had been left with no option and urged ScotRail and the Scottish Government to get back around the negotiating table.
Transport Minister Jenny Gilruth told BBC Radio Scotland's Sunday Show the staff shortages were causing "significant disruption" across the network.
David Simpson, ScotRail service delivery director, encouraged passengers to check their journey before travel.
He said: "We are experiencing a driver shortage, which means some services will be cancelled.
"We are very sorry for the disruption and inconvenience this will cause and understand customer frustration when this happens.
"Unfortunately, since the drivers' union Aslef announced it would ballot for strike action, a significant number of drivers, but not all, have declined to make themselves available for overtime or rest day working."
Gilruth described the practice of rest day working as "outdated" and said the Scottish Government was looking to phase it out.
She also said ScotRail would not have to rely on it when the delayed driver training has been completed but this was expected to take a few months.
She told BBC Radio Scotland's The Sunday Show: "We want ultimately our rail unions to have a vested interest, a stake, in the vision of the new ScotRail and what that looks like, what that means for them and their members and the staff who work on our trains. I think that is hugely important.
"At the moment rest day working continues to be needed. We are looking to phase out that practice."