Sean Coughlan BBC News Online at the NUT conference

Teachers have sent a tough message to the Chancellor Gordon Brown, saying he will have to fund the changes needed to end the dispute over workload.

Speaking at the end of the annual conference of the National Union of Teachers, general secretary Doug McAvoy called on the Chancellor to use the comprehensive spending review to finance a shorter working week for teachers.

And he warned that the union would not hesitate to take industrial action if agreement was not reached over workload and staff shortages.

An alliance of teachers' unions is campaigning for a 35-hour week, rather than the current average 53-hour working week.

Poisonous

There were signs of a deal emerging on Monday, with claims that the government was prepared to guarantee time in the school day, up to five hours a week, for marking and lesson preparation.

"Teacher shortages and government initiatives are a poisonous combination," which needed to be tackled with extra funding for education, he said.

Aiming his comments at the Chancellor, he said: "Estelle Morris had the courage to make tackling excessive workload her top spending priority. Now you must follow through."

Teachers needed "protection from exhaustion, protection from depression, protection from demoralisation", said Mr McAvoy.

And he said "the union will not back off if challenged with the demand from government that either you work with us or we don't talk to you".

'Settlement, not strike'

But the threats of industrial action were balanced with an offer of partnership with government.

"Teachers prefer partnership to collision. Teachers want settlement, not strike," he said.

And even though he commended the success of a one-day teachers' strike in London last month, he said "I don't want them to lose another day's pay if we can possibly avoid it."

The end of conference speech, which drew a standing ovation, said that angry teachers were not all "dyed in the wool militants", but were conscientious professionals struggling with 53-hour weeks and staff shortages.

Mr McAvoy also attacked the government's targets for primary schools, which he dismissed as "lunatic".

"This government is obsessed by targets. They have become a neurosis which blights everything it touches. The new targets for 11 year olds will force schools to warp and distort everything they do just to meet them," he said.

Such targets stifled creativity, he said, so that the last year of primary school missed out on "new and exciting ideas, experimenting with music, art, writing and technology".