Greater Anglia has confirmed more details of the skeleton service it is planning to offer on the main line from London if the threatened one-day strikes go ahead next week.

On the strike days, Tuesday, Thursday, and Saturday, the only lines open for passengers will be the main lines from London to Norwich and from London to Cambridge.

There will be an hourly service on the line between Norwich and London. The first train will leave Norwich at 8am and the last will leave at 4pm. From London, the first train will leave at 8.30am, the last at 4.30pm.

All Intercity trains will stop at Ipswich, Stowmarket, Diss, Manningtree, Colchester, Chelmsford and Stratford.

There will be one stopping train an hour from Colchester to London and return with the first from Colchester leaving at 7.30am and the last at 4.25pm. The first train from London will be at 8am and the last at 5pm. There will also be an hourly service on the line between Liverpool Street and Cambridge.

The 24-hour strikes will also have a knock-on effect on services on days immediately before and after the days when industrial action is taking place, so customers are advised to check before they travel on Monday, June 20, Wednesday,,June 22, Friday, June 24 and Sunday, June 26.

Jamie Burles, Greater Anglia managing director, said: “Please only travel if it’s absolutely necessary on Tuesday, Thursday and Saturday when strikes are due to take place.

“If you do travel, you should expect severe disruption, so plan ahead and make alternative arrangements to travel if you can. Please also check travel times for any journeys planned for the days before and after any strike action.

“We are very sorry for the inconvenience caused to customers by this industrial action.”

More information about how industrial action will affect rail journeys and how to apply for ticket changes or refunds are available on the Greater Anglia website.

Nationally less than a quarter of the normal 20,000 services a day are expected to run on strike days.

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.”