The ESB has described a threat of strike action by 1,200 of its technicians as totally unwarranted.
The workers, who are members of the ATGWU, claim that apprentices will be let go at the end of their training because of the company's reliance on independent contractors.
The ESB says it is very concerned about the threat by network staff, which is due to take effect at 8am next Monday.
The ESB says that the apprentices who are being trained were never guaranteed permanent jobs, but that they will be retaining half of them.
They also said that the union accepted payment in return for agreeing to the use of independent contract workers in the company's internal partnership agreement.
The ESB has accused the union of breaching procedures.
If the strike goes ahead it could disrupt repair services for local breakdowns. However, the ESB stressed that there is no threat to power generation.
