Scottish transport minister Jenny Gilruth has again written to Mr Shapps demanding action to solve the dispute between the RMT and Network Rail.
A strike involving signallers and other Network Rail staff planned for Wednesday will mean fewer than a tenth of ScotRail services will be able to run. Disruption was also expected on Tuesday evening and on Thursday morning.
Fewer trains will run in Scotland than in parts of England because more staff are members of the RMT here and fewer signalling staff are prepared to work on strike days.
The Scottish Government funds Network Rail operations north of the Border, but has no direct control in how it is run because the rail infrastructure body is part of the UK Government.
Ahead of the latest strike, Ms Gilruth wrote to the UK transport secretary, telling him: “I once again urge you to instruct Network Rail to engage in constructive negotiations with the trade unions to reach a resolution.”
She added: “Resolution for staff and passengers is possible, but it will require both political willing and focus.”
However, with the Tories going through a leadership contest to find a successor to Boris Johnson, Ms Gilruth claimed “the UK Government continues to appear to be distracted rather than focusing on resolving this dispute as quickly as possible for the benefit of rail users, staff and taxpayers”.
She spoke out as David Simpson, the service delivery director at ScotRail, said industrial action meant only “around 190” services could run on Wednesday.
The rail operator had only just returned to operating a full timetable last week – a move that meant the number of services had increased to around 2,100 a day.
However, the strike action by the RMT, which is taking place as part of a dispute over pay, means that on Wednesday ScotRail will only be able to run services on five lines in the Central Belt, with no trains at all running after 6:30pm.
This will be similar as during three previous stoppages last month, with further strikes being called by the RMT for August 18 and 20.
Mr Simpson said it was “frustrating” the strike was affecting services so soon after ScotRail had ended its temporary timetable, which had been in place because of a separate pay dispute with drivers, which has now been resolved.
Only a “very small proportion” of services would be able to run, he stated, with only about 9 per cent able to go ahead.
He said this was “very frustrating given how well things have been running since we were able to get back to normal”.
Mr Simpson explained while the dispute was a national one between Network Rail and the RMT, the action would see signallers go out on strike.
Speaking on BBC Scotland’s Good Morning Scotland programme he said: “They are critical to operating the trains, which is why we have to reduce the service to just a handful of routes tomorrow.”
Scottish Liberal Democrat transport spokesperson Jill Reilly urged the UK Government, the railway companies and the unions to “get back round the negotiation table”.