Workers who have been chucking sickies at one of Victoria's biggest power plants, forcing it to function at half capacity, have been ordered to stop unprotected industrial action.
Loy Yang power plant owners AGL says they were forced to go to the Fair Work Commission on Wednesday because "increased absenteeism and staff not being available for overtime" over an industrial pay dispute.
They say the plant hasn't been able to run at full capacity over the past six days, including on Tuesday when temperatures hit close ot 40C.
"AGL Loy Yang was forced to start the day running at 50 per cent capacity with only two of the four units available," AGL said in a statement on Wednesday.
"This was due to 30 per cent of available staff calling in sick or not being available for overtime."
The plant produces up to 30 per cent of Victoria's electricity and can experience energy surges during hot weather above 30C.
The Fair Work Commission on Wednesday ordered members of the Construction, Forestry, Mining and Energy Union to cease "unprotected action".
The industrial action is part of a long-running battle over pay and conditions.
AGL's Loy Yang general manager Steve Rieniets says the company remains hopeful it will reach a new enterprise agreement and is committed to negotiations.
CFMEU has been contacted for comment.