Scotland's largest teaching union yesterday rejected the latest pay offer.
EIS general secretary Andrea Bradley called the proposal "another inadequate offer to Scotland's teachers".
The latest offer includes a 6% pay rise in the current year and a further 5.5% in the new financial year.
Officials from the NASUWT said that, while the deal on the table was "substantially adrift from a real terms pay award", they would consider it.
Both unions have scheduled strike dates and they will remain in place.
The Scottish Government said it had found £156million to fund the latest two-year deal.
'Insufficient' offer
However, the EIS said the 6% raise for 2022-23 was insufficient due to high inflation.
The EIS, which represents the bulk of unionised teachers, has been demanding a 10% rise this year.
Ms Bradley told the BBC: "In attempting to tag on next year's pay settlement, without any negotiation at all, the Scottish Government and Cosla are attempting to tie the hands not just of teacher trade unions but all public sector unions - and this is unacceptable to the EIS."
She said the union was open to further discussions to reach a resolution to the dispute.
Education Secretary Shirley-Anne Somerville called the rejection "deeply disappointing".
She said: "It is a fair offer - the fifth that has been made to unions - and would have meant a salary rise of 11.5% for most teachers in April, with a cumulative rise of almost 30% since January 2018.
Compromise
"We looked for compromise - as we were asked to do - and dug deep under very challenging financial circumstances to arrive at a deal that is affordable and sustainable."
She appealed to the unions to continue discussions with the Scottish Government and Cosla and suspend the planned industrial action while talks are ongoing.
Patrick Roach, general secretary of NASUWT, said its members remained ready to take strike action.
He added: "Whilst we will be carefully considering this revised pay offer, it is substantially adrift from a real terms pay award and does not offer the package of pay restoration that our members would expect.
"We remain committed to securing a negotiated settlement to this dispute, while maintaining our commitment to members to secure a pay deal that fairly recognises and rewards them for the highly skilled and challenging work they do."