An indefinite strike by ESB network technicians is set to go ahead at 8am tomorrow.
The strike committee of the ATGWU said it had no option but to take official strike action because at this point there is no offer of talks from the ESB.
It blamed ESB management for cancelling a meeting scheduled for this morning in a bid to avert the strike.
Management has refused to meet the ATGWU until it withdraws its threat of strike action.
The union stresses that the dispute is about the use of external contractors.
Meanwhile, line supervisors belonging to the ATGWU have broken ranks with their union leadership, urging it to call off the strike and return to talks.
It is not yet clear how many ESB personnel will recognise the strike action.
A spokesperson for the ESB has said he does not expect power supplies to be affected by the strike but said that there could be delays for new customers coming on to the grid.
