TICKET examiners on trains will join conductors on strike over pay disputes. 

Workers in each role are involved with separate fights with ScotRail over the same issue of pay equality between grade for rest day working. 

RMT members will walk out on Sunday and the union confirmed engineering staff will also be balloted on the same issue. 

Mick Cash, the union’s general secretary, accused bosses at the rail operator of “launching attacks” on staff over social media. 

He raised safety concerns that “poorly trained managers” could be drafted in to “scab” during the strike. 

ScotRail was approached for comment.