The Australian Education Union appears poised to backflip on its endorsement of the Tasmanian Government's wages and conditions offer over concerns about the significant pay cut it would include for relief teachers.

Key points: The branch president will move a motion to reject the latest offer, which the union originally endorsed

The branch president will move a motion to reject the latest offer, which the union originally endorsed Under the proposed offer, relief teachers' loading would be cut by more than 50 per cent

Under the proposed offer, relief teachers' loading would be cut by more than 50 per cent The final decision lies with the branch council members

In an email sent to AEU representatives this week, Tasmanian branch president Helen Richardson said she would move a motion at the union's branch council meeting on Friday "to reject the Government's teachers agreement offer as it stands".

"I will ask our branch council members to reject the Government's proposed changes to relief teacher loadings and the unjustified link the Government has created between this and primary teacher instructional load reductions," Ms Richardson wrote.

Under the proposed deal, which was endorsed by the union earlier this month, relief teachers would have their loading reduced from about 80 per cent to 30 per cent, or to 50 per cent at schools able to demonstrate difficulty attracting teachers.

Tasmanian branch president Helen Richardson is asking members to reject the State Government's latest offer. ( ABC News: Annah Fromberg )

Ms Richardson has also proposed motions to change the criteria for endorsing a new offer, and to recognise that there is a "current crisis" in attracting relief teachers.

In an additional statement last night, Ms Richardson said a significant number of union members had expressed concerns about the loading cuts, and that schools were regularly forced to collapse classes because they could not source relief teachers.

She said a decision on the way forward was up to the branch council.

"No decision on the offer has been made, but it is clear the Government has failed to convince members that cutting relief teacher pay loading is acceptable, particularly when we have a relief teacher shortage crisis already in our schools and colleges," Ms Richardson said.

Last Thursday the teachers union put out a statement indicating that 70 per cent of teachers who responded to a poll on the Government's offer supported the deal. About 78 per cent of eligible union members participated in the poll.

Treasurer Peter Gutwein had welcomed the union's initial decision to endorse the offer, and said he was hopeful the shift would mean other public sector unions would follow suit.

"We would hope that other unions now follow the lead of the AEU to deliver a fair and affordable wages offer to their hard working members," he said.

Outpouring of concern for relief teachers

Earlier this month two Hobart colleges passed motions of no confidence in the leadership of the AEU, and at least one other school was considering moving a similar motion over the relief teacher issue, which could cost relief teachers tens of thousands of dollars each year.

Hobart College's Peter Hicks said there had been an outpouring of concern over what the deal would mean for relief teachers.

Elizabeth College passed a motion of no confidence in the leadership of the AEU over the relief teacher issue. ( ABC News )

"Teachers from Hobart College are quietly confident that the union has changed its mind given the strength of feedback from relief staff and their supporters that they've received," Mr Hicks said.

"We hope the union can move ahead in unity and put pressure on the Government for a just deal."

Relief teacher and union member Linda Veska said she had been stressed since she first heard about the proposed loading cut.

"I was really upset, so I sent out my point of view to all the schools that I work for, because I realised they were about to vote in this poll," she said.

"I've probably taken off three or four days off when I could have been teaching. I could have worked every day in the last two or three weeks, but some of those days I've taken off because I was just so upset because … people were about to vote."