Around 250 workers on Gama construction sites in Dublin have voted overwhelmingly to take official industrial action in support of Turkish workers who were underpaid.
The workers are members of three unions: SIPTU, UCATT and the plasterers' union, OPATSI.
SIPTU construction branch secretary Eric Fleming said the three unions are now expected to serve official strike notice early next week.
Workers have been protesting against their Turkish employers for four weeks since they discovered their wages were incorrectly calculated.
The protest has disrupted work on many of the Gama sites.
Meanwhile, the Labour Relations Commission issued proposals this afternoon to try to resolve the Gama dispute.
It is understood the proposals centre on a framework for discussions to take place over the next three weeks.
However, the LRC will be unable to engage with the parties if they are engaged in unofficial industrial action.
A spokesperson for Gama said the company has advised the LRC that it is available to attend a conciliation conference.