The Education Secretary, David Blunkett, says he has no intention of backing away from plans to introduce performance-related pay for teachers.

He was speaking after the National Union of Teachers voted to hold a ballot for a one-day strike over the issue.

The vote at the NUT's conference in Brighton puts the union on a collision course with the government over a key element of its proposals to radically restructure teachers' pay.

If the ballot backs calls for industrial action, it will lead to the first national teachers' strike for 30 years.

The vote also increases the likelihood of a boycott of a new appraisal system designed to determine which teachers should qualify for performance payments.

And a campaign of non-co-operation with government initiatives in the classroom is a step nearer.

The vote followed an address by Mr Blunkett, whose speech was interrupted by a series of hecklers.

Doug McAvoy: Believes agreement is still possible

In spite of Mr Blunkett's promise to the conference that there would be further consultation on the issue, delegates rejected any compromise over performance pay, passing an amendment refusing to participate in any pilot tests for linking pay to appraisals.

It has been widely forecast that the government will announce a slower implementation of performance pay, or begin with a pilot scheme, but such a compromise was dismissed as unacceptable by delegates.

Mr Blunkett repeated after his conference speech that the key principles of the government's proposals were "non-negotiable".

Speaking after the debate, the union's General Secretary, Doug McAvoy, said agreement was still possible - but only if the government was prepared to enter discussions without making performance pay a non-negotiable issue.

Without a single speaker opposing the call for a strike ballot, the conference heard a series of calls for the government to abandon its Green Paper proposals for teachers' pay.

An NUT executive member, Linda Taaffe, said: "Nothing short of industrial action will make the government change its mind. We can't afford to give one inch."

A delegate from Camden in London, Kevin Courtney, said teachers "competing for pay rises" would be "extremely damaging to children".

There are no dates set for ballotting members over strike action and a boycott of the new appraisal system. Mr McAvoy said the timetable would be influenced by the response of the education secretary to the conference's decision.