The dispute between British Airways and staff at Heathrow Airport will be taken to conciliation and arbitration service Acas tonight.
The dispute started after BA introduced a new clocking-in system for staff at the airport.
Some employees are refusing to co-operate, and walked out last weekend.
Staff believe the new swipe-card entry system could see them sent home during quiet periods and called in during busy times.
BA said the swipe-card system was already being used by its employees elsewhere, and was simply replacing an existing paper-based system.