Union leaders are warning of possible industrial action by workers on Eurostar trains in the run-up to Christmas.

The row is over new shift patterns.

The RMT and the Transport Salaried Staffs Association are balloting almost 100 train managers over strike action.

The RMT and TSSA called ballots,which open today and close on November 27, claiming the company had sidestepped procedures and posted new rosters without consulting local reps.