RAIL services will be “significantly affected” later this month due to industrial action, South Western Railway has warned.

Passengers will face “severe disruption” between Tuesday, June 21 and Saturday, June 25 and have been advised to start making alternative travel arrangements.

Network Rail signallers and more than 2,100 South Western Railway RMT Union members are set to strike for three days on June 21, 23 and 25.

Claire Mann, managing director of South Western Railway, said: “I understand that the announcement of upcoming industrial action will worry many of our customers, particularly against the backdrop of significant cost of living pressures.

“We are carefully finalising contingency plans, but I’m afraid this action will mean that many customers will be unable to travel by rail.”

The train operator said it is working closely with Network Rail and other train operators to finalise a significantly reduced timetable for those dates and “significant parts" of the South Western Railway would be unavailable during the strike. .

South Western Railway said where routes are open, it is likely that far fewer trains will run than normal.

Passengers are urged to change their travel dates if they can and, for those who have to travel on those dates, to begin looking for alternative methods of transport.

Ms Mann added: “If customers can change their date of travel, or make alternative arrangements, I urge them to begin making those arrangements as soon as possible.

“I appreciate how challenging this may be and would like to thank customers for their patience as the rail industry responds to this unprecedented industrial action.”

South Western Railway will publish details of its reduced timetable when finalised and customers should check the website for latest updates at southwesternrailway.com/industrial-action.