Luas drivers who are members of Siptu have served notice over their intention to take industrial action over their employment conditions.
Last March, the union announced it had started talks with management at Veolia, the Luas operator, over rostering and a decision by the company to let go staff at the end of their 12-month fixed term contracts.
The drivers rejected a Labour Court recommendation some weeks ago, and the decision by workers follows a ballot yesterday.
Drivers will now serve three weeks' notice of their action.
