The Australian Education Union's state branch on Monday vowed to increase industrial action and force possible school closures after overwhelming rejecting the state government's revised wages offer.
The government had proposed an offer of 2 per cent in the first year, 2.25 per cent in the second year, and 2.5 per cent in the third year of a new agreement.
This came with a caveat of savings efficiencies and a review of public holidays to make them more uniform.
The union's executive council has put forward a counter-offer to the government which accepted a 2 per cent rise in the new financial year but a 3 per cent rise in the following two years.
Union representative David Genford said the offer included initiatives to boost in-class support for teachers and caps on class sizes.
"Tasmania has the most disadvantaged students and the most complex students to teach so we need support in-class to provide the outcomes our students need," he said.
Mr Genford said the union had given the government one week to consider the counter-offer.
He said the offer would allow the government to better recruit and retain teachers.
Union state manager Roz Madsen said a survey of educators across 150 state schools and colleges found 83 per cent of them believed the government's offer was below expectation.
"A failure to adequately respond will leave Premier (Will Hodgman) having to explain to parents why schools will again have to be closed by the government," said Ms Madsen.
The Australian Nurses and Midwifery Union's state branch submitted a counter-offer to the government 10 days ago.
State executive director Andrew Brakey said the union expected to receive another revised offer from the government later this week.
He said this followed a series of "positive" discussions.
The Community and Public Sector Union will meet on Friday to discuss their position on the government's revised offer.