Enda Kenny described the threat as "damaging" and added that the prospect of disruption to the electricity supply is causing "unease and concern".
Mr Kenny said the dispute at the company was not about wage cuts but instead it is over the definition of a pension fund.
He called on unions working workers to engage "fully, constructive and in confidence" in talks with management.
"I agree the talk is damaging and this causes unease and concern for people'" Mr Kenny said.
He added: "This is abut hundreds of thousands of people who have made a lot of sacrifices over the last number of years and this is the last thing they want to see. And I hope therefore that the discussions that take place will end this quickly and conclusively and we can point on in 2014 in confidence. "