The state government will go to the Fair Work Commission to prevent workers at Victoria's biggest energy plant going on strike and plunging the state into an energy crisis.

"The protracted negotiations between AGL and its workforce commenced in 2015 and must be resolved," Industrial Relations Minister Natalie Hutchins said.

"The government will ask the Fair Work Commission to terminate this protected industrial action before any closure can occur."

For the second time since Christmas, energy producer and retailer AGL has threatened to lock out the entire workforce and shut down its Loy Yang A power plant in the Latrobe Valley over proposed union action.