SIPTU president Jack O'Connor has compared the campaign to the 1913 Lockout
The union representing Luas drivers says it cannot rule out an 'all-out' strike.
There will be no trams in Dublin on Easter Sunday and Easter Monday after staff overwhelmingly rejected a pay deal offering rises of almost 19%.
The strike will coincide with 1916 Rising centenary celebrations in the city centre this weekend.
Staff are also due to walk off the job again next month for another two 48-hour stoppages.
Gerry Madden of Transdev said: “The Workplace Relations Commission proposal was at the very outer limits of what we could afford and for this to be rejected is deeply disappointing". The company's pay offer has now been withdrawn".
"The drivers are being supported by the Anti Austerity Alliance / People Before Profit, who have expressed their "full solidarity and support of the Luas drivers".
SIPTU divisional organiser Owen Reidy told Newstalk Breakfast workers may step up their action to an all-out strike.
The acting Transport Minister Paschal Donohoe has called the terms of the WRC proposal 'generous' and wants SIPTU to withdraw its strike notice.
Speaking to Breakfast, he said that the prospect of an indefinite Luas strikes is "not acceptable".
He also said the priority for him is on the 1916 centenary celebrations, saying "the uniqueness of this period is understood by everyone in the trade union movement. They need to reflect on that and lead to the reinstatement of these services".
While SIPTU president Jack O'Connor told the Pat Kenny Show here on Newstalk they cannot call off their action this weekend.
During the same interview, Mr O'Connor compared the Luas drivers campaign to the 1913 Lockout - a dispute between approximately 20,000 workers and 300 employers.
And the people of Dublin have been giving their responses to the strike action.