Commuters are being warned that the vast majority of train services across Scotland will be cancelled next Monday and Tuesday.
The planned disruption is part of a UK pay dispute between Network Rail and the RMT union, which represents maintenance and operations staff within Network Rail.
While final details of amended timetables will not be confirmed until later this week, Scotrail has released early details of the services that they will be able to run on May 25 and May 26.
However they will run on a reduced basis between 7.15am and 5.45pm. All other services will be cancelled all day Monday and Tuesday.
ScotRail has launched a dedicated web page www.scotrail.co.uk/strike where they will be posting timetables for the routes that will be running during the strike.
Phil Verster, managing director of the ScotRail Alliance, said: “If this UK-wide industrial action goes ahead as planned, the impact on customers is going to be severe. For the vast majority of people in Scotland, there will be no train service at all on these two days.
“We will only be able to run a handful of services, and those that we are able to run will operate on a reduced service. Those services will be much busier than usual, so if customers are able to make other arrangements, I would kindly ask them to please do so.
“We have released this information early because it is our priority to make sure that our customers have enough time to make decisions about their journey.
“We have been in contact with employers and business organisations to let them know about the impact of the strike. We are also in touch with local authorities, the NHS and other public bodies to make sure that they are fully aware of what is happening.
“I am disappointed that our customers have to experience this level of disruption. We are doing everything we can to safely run as many services as is possible under the circumstances.”
The RMT says this dispute is about the staffing and safety on railways.
General Secretary Mick Cash said: “RMT is continuing to push for a negotiated settlement through the ACAS talks and the union is available right the way through the weekend to keep that process going if necessary.
“In the meantime our picketing arrangements are in place and the response coming back from our members is one of rock solid support.
“We would remind the public that we have been forced into this dispute through a wholly unwarranted attack on safety-critical jobs, pay and working conditions that would seriously undermine the safety of passengers on our railways into the future.
“RMT members are standing up for the principle of a properly staffed and resourced railway where safety comes first and where corners aren’t cut to hit budget targets.”