Rail passengers are being warned to expect “significant disruption to services” next week as strike action by Network Rail staff means ScotRail will operate services on just five of its routes.

David Simpson, ScotRail’s service delivery director, said travellers should “seek alternative means of transport and to only travel if they really need to”.

Network Rail staff, who are responsible for train lines and infrastructure across the UK, are set to walk out on Tuesday, Thursday and Saturday next week.

On those days, ScotRail said it would only be able to run two trains per hour on the Edinburgh to Glasgow via Falkirk High line, on the Edinburgh-Bathgate route, the Glasgow to Hamilton/Larkhall service and on the Glasgow to Lanark line.

In addition, there will be one train an hour running on the Edinburgh to Glasgow service that goes via Shotts – with services on the five lines only operating between 7.30am and 6.30pm on June 21, 23, and 25.

Meanwhile, Avanti West Coast – which runs services between Glasgow and London Euston – said it would only operate about a quarter of a typical timetable on Tuesday June 21 and Thursday June 23, increasing to about a third of services on Saturday June 25.

Mr Simpson said it was “very unfortunate to see such widespread disruption across the whole of the Great Britain rail network and we know this will be frustrating for ScotRail customers”.

He added: “Regrettably, this strike action by RMT members of Network Rail means that we will not be able to operate the vast majority of our services during the period of strike action.

“Customers should expect significant disruption to services next week, including on the days between strike action.

“On the five routes where we are able to operate a very limited service on strike days, we’re advising customers to seek alternative means of transport and to only travel if they really need to.”

Phil Whittingham, director of Avanti West Coast, said the strike action would “cause untold misery for customers”.

He added: “We’ll be running an amended timetable on strike days with fully-trained staff onboard and at stations across our network for our customers, but we’ll be operating a significantly reduced service.

“As a result, our trains may be very busy and destinations will be served less frequently, if at all.

“We’re strongly advising customers to only travel where absolutely necessary on our route on strike days and instead make their journeys on alternative days or claim a full refund.”

The warning of disruption comes as the train drivers’ union Aslef announced it would ballot its members over the 5% pay deal they have been offered.

If accepted, it could end a dispute that resulted in ScotRail having to cut more than 700 services from its timetable.

Members of the union stopped working overtime when the dispute began, resulting in a temporary timetable being put in place.

As well as increasing pay for drivers, the new deal includes more money for rest day and Sunday working, driving instructor and maternity pay, and a policy of no compulsory redundancies for the next five years.

Kevin Lindsay, the Scottish regional organiser for the union, said: “Following a meeting of Aslef’s national executive committee today, it has been agreed that the package of pay and conditions improvements negotiated between the union and ScotRail will be put to all members in a ballot. The executive is recommending members accept the deal.

“Aslef is a democratic, lay, member-led union, therefore it is right that the train drivers of Scotland decide whether or not to accept this offer. Ballot papers will go out next week and the result announced on July 11.”

A Transport Scotland spokesman said: “We welcome Aslef’s national executive’s recognition of the very good offer, an offer which is in part self-funded through increased revenue and roster flexibilities, and also that they will now take this to their members with a recommendation to accept.”

Mr Simpson said he was “pleased” that Aslef’s leaders had recommended the deal be approved, adding: “I am hopeful that the offer will be accepted and encourage Aslef members to vote in favour so that we can refocus our efforts on attracting more people back to the railway as we recover from the impact of the pandemic.”

RMT members in Scotland are also locked in a pay dispute with ScotRail, having rejected a deal similar to that offered to Aslef last week.