Unions at the ESB are meeting today to consider strike action over plans to reform the electricity market.
The unions will examine proposals set out in a White Paper on energy published last March to transfer some of the company's assets to a separate company.
Under the proposals, the ownership of the national transmission grid, which carries power from stations, would be transferred from ESB to Eirgrid, which manages the system.
The Government believes the new arrangement would make the electricity market more competitive, resulting in lower prices for the consumer.
ESB workers own 5 per cent of the company and its assets, including the transmission system.
Today's meeting is expected to hear details of a recent meeting between the unions and Minister for Communications and Energy Eamon Ryan. It is not expected that any definitive decision will be taken on strike action until the autumn.
In a statement, Sinn Féin's workers' rights spokesman, Arthur Morgan, said his party would support "any plans" to fight privatisation of the ESB.
"The planned break-up of the ESB is effectively preparing the profitable State-owned company for privatisation, and there are concerns that the recent price hikes are part of the 'fattening up' process designed to attract private interests," he said.