The RMT union has urged train guards to take the new onboard superviser roles being offered by Southern.
But the union has insisted that the three-day strike due to start tomorrow (Tuesday 11 October) will go ahead.
Southern welcomed the RMT’s new advice to members and called on union leaders to call off the “pointless” strike.
RMT general secretary Mick Cash said: “Despite the company spin there is no climbdown from the union.
“Our dispute remains on and the fight for safety continues despite the bullying and threats from Southern.
“We have a duty to issue our members with clear legal advice that protects their position in the teeth of the threat of mass sackings. That is what we have done.”
Mr Cash said that the union wanted to return to the arbitration and conciliation service ACS for talks about the long-running dispute.
But, he said, the union had been rebuffed by bosses from Southern’s parent company Govia Thameslink Railway (GTR).
Southern said that it would run more than six out of ten services during the strike this week – more trains than it ran during previous strikes.
The company added: “There will still be a restricted service, with many routes having fewer trains, and unfortunately on some routes there will be no train service at all but here there will be buses in the peak.
“On some routes, a service will be provided through ticket acceptance with other train operators. Passengers are urged to plan ahead.”
GTR chief executive Charles Horton said: “It is welcome that the RMT has finally seen sense and recommended their members take the excellent roles on offer.
“They reject an offer one day, tell conductors to sign up to the role the next, but then still issue a clarion call to strike about it a few days later.
“Their own union has lost them each a £2,000 bonus which was on offer last Thursday only to tell them to sign up 24 hours later.
“Their mandate, like their position on this six-month-old dispute, is built on quicksand.
“Now to go ahead with these strikes just days after telling conductors to accept our offer sets new standards in union militancy.
“They don’t care that hundreds of thousands of commuters will face yet more travel misery this week. It’s clear this is all about the union trying to hang on to power and control.
“We’re guaranteeing a job till 2021 and no loss of pay or overtime. Our aim is to modernise our operations to give passengers better customer service with a dedicated second safety-trained member of staff working each and every train where we currently have a conductor and the driver in sole control operating the train.
“I urge them to call off what is a pointless and unnecessary dispute, as it always has been.”