A CHRONIC shortage of teachers across Australia has left more than two-thirds of the nation's high schools struggling to recruit essential staff, a landmark survey of teachers has revealed.

The survey provides compelling new evidence of a profession in crisis, with shortages of qualified people in subjects including maths, science, information technology and languages.

Many schools were requiring staff members to teach outside their field of expertise to cope with the shortage, the survey found. Some principals were also combining classes across year levels, sharing programs with other schools and reducing their curriculums.

The report comes a day after it was revealed that demand for places in undergraduate teaching courses in Victoria this year had slumped by 6.8% — a trend blamed by the teachers' union on poor pay and a lack of job security in state schools.

About 13,000 teachers and principals in the public and private school systems took part in the national survey. Of those, about 70% agreed that higher pay based on competence or extra qualifications would help retain more teachers.

More than 85% also believed more support staff, smaller class sizes, reduced workload and a more positive public image of teachers would help retain people in the profession.

The report comes as the Rudd Government faces another political challenge on education today, with the Australian Education Union pushing for an ambitious — and expensive — reform agenda at its annual conference.

On top of an extra $2.9 billion it wants spent on public education, the union will call for targeted funding to increase teacher pay, reduce class sizes, provide 20 hours a week of early childhood education for all four-year-olds and improve infrastructure at dilapidated schools.

It will also seek $1.7 billion over five years to enable 7500 indigenous students in the Northern Territory to access schools and an additional $470 million this year for TAFEs.

And the conference will criticise the new Labor Government for retaining what it calls a "corrupt and discredited" private school funding model.

The teaching report, by the Australian Council for Education Research, found that 43% of Australian secondary principals required teachers to teach outside their field of expertise.

As well as shortages in maths, science, foreign languages and information technology, data also suggested critical teacher shortages in English, the performing arts and special needs.

Only 40% of senior secondary information technology teachers had completed at least three years of tertiary education in their subject, and only 60% of physics teachers had done so.

Federal Education Minister Julia Gillard said that to tackle shortages in maths and science, the Government would halve HECS contributions for students studying these subjects, and halve their repayments again if they went on to teach them.

But Australian Education Union president-elect Angelo Gavrielatos said Ms Gillard had under-emphasised the need to address the teacher shortage.

"The report highlights the most important things that need to be done to retain teachers are to provide more support staff, smaller class sizes, reduced workload and fewer changes being imposed on schools," Mr Gavrielatos said.

Teachers also needed salaries that compared favourably to other professions in order to attract and retain people, he said.

Classroom teachers are eligible for incremental pay rises each year until they hit a ceiling after about 10 years.

In Victoria, the ceiling is $65,414 — the lowest level nationally — unless teachers take on a leadership role.

The president of the Victorian branch of the Australian Education Union, Mary Bluett, said the Victorian Government spent less per student on education than any other state or territory.

"Teachers at the top end of the scale receive 15% less than their NSW counterparts, which equates to nearly $10,000 per year," she said.

"Further, almost one in five teachers are currently on short-term contracts and close to 80% of first-year teachers commence on one, which is particularly discouraging for those looking to enter the profession."

Only 40% of senior secondary information technology teachers had completed at least three years of tertiary education in their subject, and only 60% of physics teachers had done so.

Federal Education Minister Julia Gillard said that to tackle shortages in maths and science, the Government would halve HECS contributions for students studying these subjects, and halve their repayments again if they went on to teach them.

But Australian Education Union president-elect Angelo Gavrielatos said Ms Gillard had under-emphasised the need to address the teacher shortage.

"The report highlights the most important things that need to be done to retain teachers are to provide more support staff, smaller class sizes, reduced workload and fewer changes being imposed on schools," Mr Gavrielatos said.

Teachers also needed salaries that compared favourably to other professions in order to attract and retain people, he said.

Classroom teachers are eligible for incremental pay rises each year until they hit a ceiling after about 10 years.

In Victoria, the ceiling is $65,414 — the lowest level nationally — unless teachers take on a leadership role.

The president of the Victorian branch of the Australian Education Union, Mary Bluett, said the Victorian Government spent less per student on education than any other state or territory.

"Teachers at the top end of the scale receive 15% less than their NSW counterparts, which equates to nearly $10,000 per year," she said.

"Further, almost one in five teachers are currently on short-term contracts and close to 80% of first-year teachers commence on one, which is particularly discouraging for those looking to enter the profession."