Esso has locked out maintenance workers from its oil and gas plants in Victoria and its offshore platforms in Bass Strait.
The move is part of an enterprise bargaining agreement (EBA) dispute with members of the Electrical Trades Union (ETU) and the Australian Workers Union (AWU).
Unions had imposed bans on overtime and call-outs as part of their campaign against Esso’s proposed changes to pay and conditions. The lockouts affect the Longford gas plant, Long Island Point and Esso's oil and gas plants in Bass Strait.
Esso put forward several proposals for Longford Gas Plant workers, including having offshore workers work two-week shifts rather than one week on and one week off. But 90% of its workers rejected the proposals.
The AWU’s Victorian branch secretary, Ben Davis, said it was preparing a counter proposal to present to the company in the next few weeks but there was no end in sight for the negotiations.
"I was hoping that Esso would see from the result of the ballot that there was no chance that they could coerce their employees into doing what they wanted," he said.
"I was hoping it'd be a reality check for them. I don't think it has been.”
The maintenance workers will be locked out for two hours a day. Peter Mooney from the ETU said the lockouts would delay important maintenance work and could raise safety issues.
"We've had no meetings where there's been any opportunity to progress with the unions and the company," he said.
"The company is taking the position that it will continue to press with its claims, which are untenable to our members."