"Does anybody seriously think if they were offered an above-inflation pay increase followed by an increase of up to 10% followed by re-grading proposals that took them up to £35,000 they would go on strike?"

David Blunkett rejects criticism of the teachers' pay deal on Radio 4's Today programme

Mr Blunkett was responding to threats of "direct action" from teachers' union leaders over this year's pay settlement which has awarded classroom teachers 3.5% and primary headteachers up to 9.5%.

"The government seems determined to push teachers towards industrial action," said Doug McAvoy, the General Secretary of the National Union of Teachers, who accused the pay deal of revealing "complacency" and "hostility towards teachers".

Doug McAvoy threatens "direct action" against government policy

But the Education Secretary, David Blunkett, rejected such claims, saying that the settlement for headteachers was a necessary step towards an appraisal-based system for all teaching staff, which will lead to many receiving higher salaries.

"Everyone knows we can't simply massively increase the starting salaries of all teachers and say the sky's the limit," said Mr Blunkett.

"The bottom rung of the ladder might not be the most wonderful position in the world. But for most teachers it is £15,500 and the real issue is where they will be in 10 or 15 years time.

"The proposals we are putting forward mean there will be a substantial boost for those teachers who currently hit the ceiling of £22,500,"

Doug McAvoy, on Radio 4's Today programme, predicts unrest in the classroom over pay

But Mr McAvoy insisted that teachers deserved rewards in the short term as well as the long term and called for a "joint campaign of all the teachers' organisations" to press the government for more pay.

"That campaign could lead to direct action on class sizes, on cover for absences and on the increased workload teachers face in their own time.

"Teachers were disappointed last year that their increase was staged. This year, they will be angry that their commitment and dedication leads to nothing more than low pay."

The 3.5% increase, he says, represents only a single percentage point rise above inflation and means that teachers "have not caught up with where they were three or four years ago".

"Direct action becomes more and more likely while the government maintains its complacency towards teacher shortages and hostility towards teachers."

Nigel de Gruchy says an opportunity has been wasted to improve morale

The Association of Teachers and Lecturers were also unimpressed by the pay settlement. General Secretary, Peter Smith, described the rises as "a spin too far".

"A sensible discussion about performance-related pay for teachers cannot even get off the ground until there is a guarantee of proper funding. Today's announcements on teachers' pay will not reassure teachers that there will be that guarantee."

The extra payments to headteachers, he said, were only "reshaping the problem, not solving it".

Also expressing his disappointment at the pay settlement, Nigel de Gruchy, the General Secretary of the National Association of Schoolmasters Union of Women Teachers, said that "an opportunity to improve the atmosphere in teaching has been scandalously squandered".

David Hart has welcomed recognition of headteachers' responsibilities

While he welcomed a "decent rise for heads", Mr de Gruchy said that it was "a serious error of judgement for the government to treat classroom teachers in such a shoddy way.

"Heads will not be helped in their jobs if they have demoralised teachers to manage along with more severe recruitment difficulties."

Calculating the eventual rise for headteachers is extremely complex. The government is introducing a new pay scale, linked to points derived from the numbers of pupils of different ages in a school. The government claims there may be rises of up to 9.5% overall for heads of small primaries - more like 5% on average for typical secondary school heads.

The General Secretary of the National Association of Head Teachers, David Hart, said: "I think it is potentially good news for many heads but the devil will be in the detail."