A UNION is to ballot ScotRail engineering staff over strike action as ticket examiners and conductors prepare to walk out tomorrow.

RMT confirmed that strike action over the issue of “equality between grades in payments for rest day working” will go ahead as planned. Earlier this month ticket examiners voted in favour of walkouts over the dispute and tomorrow marks the first of their six weeks of action.

This weekend was due to be the last of six Sundays of strikes by conductors but, from May 9, these workers will begin another six Sundays of action.

The union said that it will shortly begin balloting engineering grades over the same issue of “workplace justice on enhanced payments”.