About 500 teachers from the southern Melbourne region, including staff from Huntingdale Primary School, Monash Special Developmental School, Oakleigh South Primary and South Oakleigh College, went on strike, with many taking part in a rally at Treasurer John Lenders' office.

One of their demands is for the Government to bridge a $10,000 pay gap between many of Victoria's teachers and their New South Wales counterparts.

The Australian Education Union's Victorian branch secretary, Mary Bluett, said comments by Education Minister Lynne Kosky derailed negotiations last week. "Just when we thought we were close to settling, we were rocked by the minister going on radio saying we were to lose three pupil-free days for a pay increase."

Ms Bluett said two of those days were required for report writing and were non-negotiable.

The dispute, which began with negotiations 14 months ago and a stop-work rally last November, had gone too long, she added.

This month, Opposition education spokesman Martin Dixon toured schools, including Mount View Primary on April 19, spruiking Liberal leader Ted Baillieu's promise to make Victorian teachers the best paid in Australia.

Ms Bluett said the Liberals' promise, with the rolling stopwork rallies and community support, had added pressure on the Government.

"Most of the community want us to be paid at least as much as NSW teachers. It was good politics by Ted Baillieu to pick the community mood. I'll also say it's the first time for a long time that a politician has said he'll make us the highest-paid teachers in the country, highlighting the incredibly important work we do."

The State Government did not comment before publication.