RAIL companies are urging people to avoid unnecessary travel as half of Britain's rail lines will be paralysed by industrial action next week.

Members of the Rail, Maritime and Transport Union at Network Rail and across 13 train operators are set to strike for three days in disputes over pay, jobs and pensions.

The strike days are planned for Tuesday, June 21, Thursday, June 23 and Saturday, June 25.

Lines that remain open will only operate between 7.30am and 6.30pm, meaning services will start later and finish earlier than usual.

Network Rail has urged passengers who must travel to plan ahead to ensure they can complete their journeys within this narrow window.

Only around 12,000 to 14,000 services will be able to run on the days following the strikes.

Steve Montgomery, who chairs industry body the Rail Delivery Group, said: “These strikes will affect the millions of people who use the train each day, including key workers, students with exams, those who cannot work from home, holidaymakers and those attending important business and leisure events.

“Working with Network Rail, our plan is to keep as many services running as possible, but significant disruption will be inevitable and some parts of the network will not have a service, so passengers should plan their journeys carefully and check their train times.”

While Thameslink and Southern Rail workers are not among those striking next week, both train operators urged passengers to “only travel if your journey is absolutely necessary and expect disruption”.

They also warned services will be severely disrupted on Wednesday, June 22 and Friday, June 24, with an amended Sunday service and no services operating before 7.15am.

Journey planners for strike days are expected to be updated by National Rail on Friday, with an amended timetable for next Wednesday and Friday due to be updated on Saturday.

A spokesman for Thameslink urged those travelling during the industrial action to “check again before any necessary journeys before travelling as there may also be changes on the day to the planned service”.

He said: “Ensure you have checked when your last train departs as there will be no alternatives once services end.”