Some 40,000 teachers took part in what could be Victoria state's biggest teachers' strike that forced 400 schools to close and left thousands of school kids to stay home these past days.

This developed as the Australian Education Union (AEU) refused the 2.5 per cent pay rise with performance bonuses offered by the Victorian Government. The AEU made good its statement in July that it will hold the massive industrial work stoppage this first week of September.

The industrial action was a result of a lengthy pay dispute with the state government, according to AEU President Mary Bluett, noting that since the June strike, the Victorian Government failed to restart negotiations.

"We hope today's strike changes the Government's approach. And then avert the further action that may flow if we don't get an agreement before the end of the year," she told ABC News.

About 15,000 teachers gathered at Rod Laver Arena, dressed in red, to rally as well as to vote on further industrial action, including implementing rolling stoppages and work bans, which would only be suspended during VCE exams.

The teachers then marched to Parliament House where thousands of Catholic school teachers joined them.

Peter Martin, Principal of Port Melbourne Primary School, and who joined his staff who took part in the strike, said the school community supports the strike.

"I've never seen a statewide strike like today. There are not just teachers, there are ancillary staff, private schools, Catholic schools," he said.

"This is by far the largest teachers' strike that I've been involved in in 40 years."

"We gave notice of this stop-work a month ago and we've encouraged schools to let parents know," Ms Bluett said.