Up to 15,000 Victorian teachers and support staff have packed Melbourne's Rod Laver Arena as part of strike action for better pay and conditions.
The teachers and staff, who are engaged in a long running industrial dispute with the state government, are expected to vote on a range of further industrial action before marching to the Victorian parliament on Wednesday.
Kaz Sieger, who is a primary school music teacher in Melbourne's east, said it was time for teachers' pay to adequately reflect the work they do.
"Teachers are striking to get pay that hopefully reflects the amount of work that they do for the community," he told AAP as he prepared to enter the arena.
"We are definitely at a time where we need to look at how teachers are paid and what's fair."
The arena, which holds about 15,000 people, is full.
The Australian Education Union (AEU) wants a 30 per cent pay increase for teachers over three years and more job security for teachers and support staff, many of whom are employed on a contract basis.
The Baillieu government is standing by its offer of a 2.5 per cent rise, which it says will also see an additional 70 per cent of teachers get a substantial bonus each year.
It says the union's demands are unreasonable.
AEU Victorian president Mary Bluett said at least 220 schools had confirmed their closure on Wednesday, but she expected the total number to be closer to 400.
Ms Bluett said 15,000 teachers and staff were expected at the main rally in Melbourne, and thousands more were likely to attend other rallies around the state.
She said union members would vote on a range of further industrial actions, including rolling half-day stoppages from next term, another full-day strike in February and refusing to work extra hours for activities such as camps, sports and musicals next year.
The state government estimates about 65 per cent of teaching staff and 35 per cent of non-teaching staff will take Wednesday off.
Victorian Teaching Minister Peter Hall said the AEU's strike would "disrupt the lives of hardworking Victorian families".
He defended the government's proposal to reward teachers based on individual performance, saying principals had told the government that such a system could be applied more rigorously than one that rewards the whole school.
"(The government's offer) would provide a fair and balanced system for identifying the poor performers in our schools, and give us a chance to build their professional development," Mr Hall said in a statement on Wednesday.
- Have you been affected by today's strike? Do you agree with the action? Leave your comments below.