Union officials are to meet with 200 Polish workers at the ESB's Moneypoint power station after the company with which they work had its contract terminated.
The Technical, Engineering and Electrical Union claimed that many, if not all, of the Polish workers concerned had not been paid in the past six weeks.
The decision to cancel the contract of the Polish company was taken by the Lentjes group, which holds the overall contract from the ESB for work at the site.
The ESB said it was aware of a number of outstanding issues with the Polish sub-contractor in relation to its compliance with labour and employment law in Ireland. This followed monitoring of the company by the ESB.
Dan Miller, the TEEU's Assistant Secretary General, said he would be seeking a meeting with the workers on Monday, as well as with the contractor and the ESB to discuss pay.
He said the union would also be seeking to find out if the workers could be employed by any new contractor who came in to complete the work.
