ATGWU shop stewards last night defended their decision to go ahead today with a strike at the ESB which is not supported by other unions.
They claimed they had "no option" but to strike after the company cancelled a planned meeting yesterday with the ATGWU and two other ESB unions.
The ESB said it was not prepared to negotiate while a threat of industrial action was in place.
The strike by 1,200 network technicians is over the extent to which outside contractors are to be involved in the delivery of a €3.6 billion programme to upgrade and modernise the company's network.
About 1,700 external contractors are at present employed by ESB Networks alongside some 2,200 staff technicians. Those not in the ATGWU are represented by the TEEU or Siptu.
In a statement yesterday read to journalists, the ATGWU's network technicians' strike committee said it had made clear at every stage of the dispute that it was open for talks any time. However it claimed there were "no offers of talks from ESB".
"In order to clarify the position as it stands: this dispute is about contractors. We are fighting for the protection of continued employment for all of our members going forward."
Committee members refused to take questions from journalists, and said there would be no further statement.
Brendan Ogle, the senior union official involved in the dispute, was not present when the statement was read.
The ESB said it strongly rejected the assertion that it was not willing to engage with the union on the issue of contractors.
"ESB has been involved in an ongoing talks process with the three unions representing network technicians for the last number of months," it said in a statement.
"ESB's offer to again meet all three unions, following the withdrawal of the ATGWU strike notice, still stands."
The extent of support for the strike will not become clear until pickets are placed at ESB depots at 8am today.
The TEEU and Siptu said yesterday that members were being instructed to work today, although not to do work normally done by ATGWU members.
In spite of their unions' stance, however, TEEU and Siptu network technicians may be reluctant to pass colleagues' pickets.
However, more worryingly for the ATGWU, there were also indications of dissent from within the union's ranks yesterday.
In separate statements, ESB supervisors who are members of the ATGWU and the union's Dublin South committee called for the strike threat to be withdrawn. Both statements were issued from the same e-mail address, however, and a phone number supplied for verification was not answered.
In its statement, the union's strike committee said 91 per cent of the network technicians had balloted for industrial action.
