Tram drivers demanding pay increase plan two 48-hour work stoppages next month.
Commuters face travel chaos after Luas staff announced plans to stage two 48 hour strikes next month.
Workers will down tools on February 11 and 12 and again on February 18 and 19 - both Thursdays and Fridays - causing mayhem for commuters and shoppers just ahead of the General Election.
The Siptu trade union confirmed three of four groups of workers, who balloted overwhelmingly to take industrial action, preferred to strike for 48 hours at meetings this week.
A majority of the 180 drivers, 37 revenue protection officers, and eight revenue protection supervisors backed the option.
The fourth and final group of staff - 16 control room officers - will work to rule on those dates.
Luas operator Transdev released figures claiming drivers are seeking a massive pay rise of almost 54pc.
It said tram drivers on €42,247 a year are seeking a 53.8pc increase to €64,993 - substantially more than an Irish Rail driver.
Siptu would not give a complete list of all its demands - but maintained drivers want a pay rise in the region of 30pc over five years, with a similar increase being sought by other staff.
The union has also sought improvements in annual leave, bonuses, pensions and income continuance.
Union official Willie Noone said workers believe they have been underpaid for years while working with a huge amount of passengers in a congested environment 24 hours a day, 365 days a year.
He said the company claims it has no room for manoeuvre because it commits to keep pay in line with inflation, which stands at zero, in its tender documents.
"That means we're now hamstrung, and these tenders are submitted without consultation with the drivers," he said.
"There has to be real progress made on the claim as there was such a high turnout at the ballot and an overwhelming vote that showed there is huge discontent, and that will not be easily abated."
The union is likely to give three weeks' notice of industrial action later this week.
Transdev said the pay claims lodged by tram drivers are between 8.5pc and 53.8pc and would cost it €30m over its five year operating contract, or €6m a y ear.
It said it lost €700,000 last year, and predicts further losses again this year.
It pointed out that Luas staff get bonuses on top of their salaries which can amount to up to 6.5pc per employee and be worth between €2,200 and €3,000 a year.
"It is disappointing for us to learn that union employees plan on stopping the Luas service in pursuance of their pay claims," said Transdev managing director, Gerry Madden.
"We believe the pay and terms and conditions of Luas employees are, and always have been, very favourable."
Transdev said the Labour Court recommended that "meaningful" talks were held at the Workplace Relations Commission, and this was the only way the dispute could be resolved.
Siptu utilities and construction division organiser, Owen Reidy, said: "The workers are conscious of the inconvenience these stoppages will have on their customers but believe they have no option but to conduct this industrial action."