A large private school in Melbourne's outer west has been put into voluntary administration, leaving over 1,200 students in a precarious position.

Mowbray College in suburban Melton has suffered a severe financial breakdown.

Administrators are doubtful they will be able to keep the school open and parents are scrambling to find other schools for their children.

The college was placed into voluntary administration on Tuesday with debts of $18 million.

The Baillieu Government has brought forward a $400,000 grant to keep the school open until the end of term.

Administrator Jim Downey says the school's financial situation is in a "parlous" state and it will be tough to keep it open.

"My aim is to keep the doors open through to the end of the term," he told ABC local radio.

"For the period that I operate the school, staff can be assured they will be remunerated for their time."

Mr Downey says times are tough and families are having trouble paying their school fees.

He says the school is owed about $2 million in unpaid fees.

Families of the students are distraught over the impending closure, saying local schools are already filled to overflowing.

Parent Cathy Stewart says they saw the warning signs and have arranged for their young son to be sent to another school.

But other families are not as lucky.

"A lot of people are very distressed," she said.

"Schools in the area, they're full, or there are waiting lists."

Vicky, the mother of a Year 12 student at the school, says the situation is even more dire for her son.

"He's doing the IB, which is the International Baccalaureate, which Mowbray has been offering," she said.

"There are very limited number of schools offering the IB around Melbourne."

Opposition Education spokesman James Merlino says the Government must do more to help.

He says it would be a tough ask to relocate all 1,222 kids to new schools before the start of the next term.