Network technicians at the ESB have threatened to strike from next Monday in a row over the role of outside contractors.
Power supplies will not be immediately threatened if the action by more than 1,000 ATGWU members goes ahead, but a prolonged strike could lead to blackouts. This is because repairs would most likely not be carried out in the event of breakdowns in the company's distribution network.
The ESB said yesterday it was "very concerned" at the threat, which it described as "totally unwarranted".
The dispute is over the extent to which outside contractors are 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, more than half of whom are represented by the ATGWU.
ESB Networks operates the ESB's State-wide distribution system, which includes 170,000 transformers and almost 150,000km of overhead lines and underground cables.
The ATGWU says a number of ESB apprentices are unable to secure jobs with the company because of the extent to which outside contractors are being used. Its members balloted last month in favour of industrial action.
The ESB's position is that the current role of contractors is in line with a comprehensive agreement drawn up with unions in 2001, known as the Pact.
As part of that agreement, temporary general workers, whose jobs were to be phased out, were given the opportunity to become apprentice electricians.
While there was no guarantee of employment with the ESB at the end of the process, 56 of the first 107 graduates, who will be completing their courses shortly, have been offered jobs with the company.
The ATGWU's ESB representative, Brendan Ogle, said the union was not arguing all apprentices should be guaranteed jobs with the company. But they should be employed where work was available, he said. He claimed external contractors were being used to carry out "core work", which was a breach of the Pact and resulted in apprentices being denied jobs.
Mr Ogle said the strike could be avoided if the ESB agreed to enter negotiations on a new agreement, which recognised the positions of both sides concerning the use of contractors and jobs for apprentices, to succeed the Pact.
An ESB spokesman, however, said the company was already involved in an ongoing process with all of its unions regarding pay, pensions and future change across the company. By threatening to strike, the ATGWU had taken itself outside that process.
The spokesman said industrial harmony at the ESB had been achieved through agreed industrial relations procedures, which had been respected by management and unions, including the ATGWU.
It was imperative that all parties remained committed to maintaining the integrity of the industrial relations framework in place, he said. No meetings between the sides had been arranged by last night.