Southern rail strikes: 24-hour walkout to be held instead of back-to-back strikes

RMT general secretary Mick Cash accused Southern of a "hostile and aggressive stance", saying the union had "reassessed the tactics of the dispute".

He said: "Southern should be under no illusions - the union will not bend to their bullying and threats, and we will be building on the huge public support we have already mobilised in a campaign that pitches the demands for increasing private profits against safety on our railways.

"Southern fleeces its passengers for a fortune in fares for unreliable and overcrowded services and RMT will not allow safety to be the next thing sacrificed in the dash for fatter and fatter profits on this rail franchise."

But Southern branded the strike "totally unnecessary" and claimed the changes were already in place on 40 per cent of its services.

A spokesman said: "We are naturally pleased that next week's strike has been postponed, but remain concerned that the threat of further strike action hangs over our passengers with a new date announced for May 20.

"While it would be good to think the RMT has changed its position, we believe they have taken this action after members rebelled at the prospect of losing a significant sum in pay and benefits due to the union calling three strike days in the same pay period.

He added: "No one will be made compulsorily redundant and no one will lose salary.

"We hope this additional time will offer the RMT the opportunity to pause and reflect on the impact their action is having on people and engage in meaningful discussions with us."