The Tánaiste Eamon Gilmore says the public will have no tolerance for electricity supply disruption after staff at the ESB voted overwhelmingly in favour of industrial action.
Mr Gilmore has called on unions and management to resolve their dispute over pensions through negotiations.
Speaking on his way into Government Buildings this morning, the Tánaiste called for both sides to enter talks.
He said: "I think that problems relating to the pension in the ESB should be resolved around the table.
"I think the public will have no tolerance for disruption of the electricity service or power cuts, so I think the issue needs to be resolved around the table."
Brendan Ogle, secretary of the ESB group of unions, says it is very likely workers will down tools.