She was called into the principal's office and told she was no longer needed.

Fiona* had been declared "excess" – a process that lets cash-strapped state schools trim their budgets by axing staff.

"It has been painful and I'm still traumatised by it," she says.

"You don't expect to have to reinvent yourself at the age of 58."

Figures obtained under Freedom of Information show that 10 times as many experienced teachers were declared excess between mid-2013 and the start of this year compared with more junior teachers.

Of the 417 Victorian teachers who were told they must find new jobs, 363 were "classification two" teachers, many of whom had worked in schools for decades. They earned between $75,940 and $94,961.

A further 16 of the most senior "leading teachers", who earned between $99,424 and $104,296, were told they weren't needed.

This compared with just 38 excess teachers in the most junior "classification one" category.

Classification one teachers, who usually have less than five years experience, were earning between $63,356 and $73,238.

Melbourne teacher Judith Crotty requested the data after noticing that it was predominantly older teachers who were asked to leave.

She says the data shows the process of determining excess teachers discriminates against older, more experienced teachers, who earn more.

"It's demoralising," Ms Crotty says.

"I understand why schools are doing this, they want to fix their budget. I would like to see the government fund schools properly to avoid this situation."

More than one in five Victorian state schools were in deficit at the end of last year, and when a school plunges into the red, staff, programs and VCE subjects are the first thing to go.

"You have to make decisions about someone's life," one principal, who is battling a $1 million deficit, says.

Teachers who are placed in excess say they are often replaced by cheaper, younger teachers.

Critics say it robs schools of talented teachers who have devoted their life to the profession.

The Australian Education Union says schools need to be properly funded to avoid deficit and retain experienced staff.

"From time to time some schools face significant challenges in managing their budgets, especially when student enrolments are declining due to changing demographics in their local communities," says Justin Mullaly, the deputy president of the union's Victorian branch.

"In any instance where we can determine that a union member has been unfairly placed in excess we will support that member in pursuing the issue."

An Education Department spokesman said that less than 0.25 per cent of all teachers were declared excess every year.

"We understand the impact that being declared excess can on those involved and work closely with schools with changing staff requirements to thoroughly explore other options before a staff member is declared excess," he says.

"Declaring staff excess is a school-based decision, however we would be concerned to hear of schools discriminating against teachers based on their age and would encourage anyone with information about this happening to contact us."

Fortunately Fiona found work at another school after completing further postgraduate studies.

She considers herself lucky.