As a furious Ms Morris issued a stark message to the unions not to undermine the government's drive to raise school standards by taking industrial action, the largest classroom union, the National Union of Teachers, published the results of a ballot showing overwhelming support for a one day strike next Thursday over London allowances.
But Ms Morris also rounded angrily on the usually moderate headteachers' organisations, saying she was "puzzled and surprised" by plans for a parallel ballot over performance related pay.
Her hard line looks certain to create a confrontational climate at the annual round of teachers' conferences this month. She is due to address the NUT's conference in Bournemouth.
Ms Morris told an education conference in London: "It would be tragic if the irresponsible action of a few damaged the impact of work already achieved to build a teaching profession that is the source of national pride and the envy of the world. My challenge to unions is to work with us. The alternative is to return to the dark ages of dispute and conflict."
She warned that the NUT's "absolutely nonsensical" action risked harming children's education and damaging the profession's reputation.
An NUT member herself, she recalled the damage the strikes of the mid-1980s had on teachers' public standing and on the prospects of a generation of pupils. "I can remember how awful it was. That's partly why I feel so strongly. I've been there with the NUT and it achieved nothing - it jeopardised education for a whole generation of kids and it achieved nothing."
But she also made clear she was furious over threats by the Secondary Heads Association and the National Association of Head Teachers not to do the work required to process claims for performance bonuses for teachers.
Next Thursday's industrial action will be the first over London allowances for nearly 30 years, when Margaret Thatcher was education secretary. The NUT wants the allowances increased by more than a third, while the government has offered just 3.5%.
The results of the ballot showed that 86% of NUT London members supported the one day stoppage, but on a turnout of just 30%. The government said that overall, only 13% of London teachers supported the strike call.
Teachers' leaders expressed their anger over Ms Morris's remarks.
David Hart, general secretary of the National Association of Head Teachers, said: "The last persons in the education world who need a lesson from the secretary of state on public service reform are headteachers. It is unbelieveable that the government seeks to pick a fight with the very people who have delivered and delivered and delivered again on the government's standards agenda."
John Dunford, general secretary of the Secondary Heads Association, said: "This is disingenuous of the secretary of state to say that she is 'puzzled and surprised' by our ballot, the first in the history of SHA. We have tried to negotiate changes with the department but the secretary of state has been intransigent in her allegiance to this disastrously underfunded system."
