The conditions that train drivers work under are far more rigorous than those of Luas drivers, according to the National Bus and Rail Union.

Luas workers are seeking significant pay increases, and a strike yesterday was only averted by last-minute marathon talks.

Luas drivers want to be paid on the same scale as drivers at Irish Rail, and bus drivers want to also benefit from any pay increases given to Luas workers.

However, general secretary of the NBRU Dermot O'Leary said the work Luas drivers and train drivers do is different.

"There is a vast difference, a vast gulf, between the duties of a train driver and a tram driver - one being heavy rail and one light rail," he said.

"Some of the conditions and standards train drivers work under are far more rigorous than those of a Luas driver, with respect to Luas drivers."