The move was part of a campaign by the Electrical Trades Union to try to protect its members from forced redundancies.

ETU secretary Steve Butler said it had been a long time since Endeavour Energy workers had gone on strike over an enterprise agreement.

"I would say it's been well over 10 years, maybe 15 or more since there's been strike action in relation to an enterprise agreement," Mr Butler said.

"There hasn't been a stoppage in a long, long time and that's because the guys are quite considered when they sit down and talk about agreements. They're usually very respectful and reasonable in relation to the employers' position but because there's been no progress then that approach has not worked, so they've had to step it up."

Mr Butler said the workplace agreement with Endeavour expired over three months ago.

There was a provision stipulating no forced redundancies in that agreement and the union wants it included in the new one with the spectre of electricity privatisation somewhere in the future.

"This action is to send a message to the state government and to Endeavour that the guys are very keen to make sure that any new enterprise agreement has provisions in it that [there be no] forced redundancies," hesaid.

"We're looking for commitments for it to be continued but at this stage we're not getting those commitments."

Endeavour Energy has said it was not able to commit to anything about redundancies ahead of a determination of its budget.

The electricity company's budget is set by the Australian Energy Regulator. In a draft determination, the AER has cut Endeavour's proposed budget by 30 per cent to $3057 million.