The industrial body representing Victoria's hospitals has made an application to Fair Work Australia to halt the industrial action by the state's nurses.

The nurses have closed up to 800 hospital beds across the state in a pay dispute with the Victorian Government.

The hospitals say the action is putting patient safety at risk.

Nurses have closed around 700 of the state's 13,000 hospital beds in pursuit of an 18.5 per cent pay rise over four years.

They also want a guarantee that nurse-to-patient ratios are not changed.

The Health Minister David Davis says the number of bed closures is likely to escalate rapidly today.

"As elective surgery ramps up there will be a great deal more pressure on the system," he said.

"Emergency departments are vulnerable if there is a significant increase in demand and that demand can certainly impact very severely."

Mr Davis says the bans are having a widespread impact on hospitals and are a threat to patient safety and welfare.

"The Victorian Government is not prepared to stand by and allow that to occur," he said.

The state secretary of the Australian Nursing Federation (ANF) Lisa Fitzpatrick says the campaign has been designed to ensure people in dire need of medical care do not go without.

"Nurses would never ever threaten patient safety health or welfare in this entire state," she said.

"In fact, our bans ensure that that doesn't happen.

"We do know that people will experience delays and we've apologised for that."

The chief executive of the Austin Hospital Brendan Murphy says hospitals do not want to get rid of nurse-patient ratios.

They want to increase flexibility.

"You can only start nurses at [specific] times of the day, they can only work 8 or 10 shifts with only slight exceptions," he said.

"You can't flex up when you have busy periods and not flex down when you are not busy.

"You can't allow young mums who want to work a four hour shift to do, because it is illegal under the union rules."

He says the dispute is putting huge pressure on the hospital's emergency department.

"We've had three patients breach the 24 hour [period]. We haven't' seen that stay in emergency for years," he said.

"We've had 17 patients in the emergency departments this morning, each of whom we have to negotiate with the union about whether we can get into a bed, and that creates risk."