The Ministry of Education and the secondary teachers union are blaming each other for the chaos created by the late cancellation of Thursday's teachers' strike.
Principals are angry they were told too late on Wednesday that the strike affecting year 10 students was suspended.
They say the late notice caused chaos, with many year ten students not going to school yesterday.
The Post Primary Teachers Association says it told the Ministry of Education the strike would need to be cancelled on Tuesday, if at all, and it would only do that if there was progress in the pay talks.
The union says there was no progress on Tuesday but on Wednesday the Government insisted the strike be dropped and said there could be progress on class size if the talks continued.
PPTA president, Kate Gainsford, says there was no progress on that issue.
She says she detects an "absolute reluctance to settle" on the part of the Government, and is suspicious about "the game playing that has featured throughout this round."
Secretary for education Karen Sewell says there has been steady progress in the talks and the union could have called off its strike earlier than it did.