By Gary Eason BBC News, at the NUT conference

Teachers say the current pay deal as a 'standstill award'

The annual conference of the National Union of Teachers backed a motion from its leaders to prepare a ballot on a one-day strike with other unions.

Unions are unhappy that their current two-year deal with 2.5% rises this year and next has fallen behind inflation.

The government says a strike would serve only to disrupt pupils' learning.

The Education Secretary, Alan Johnson, has asked the independent School Teachers' Review Body to recommend a new, three-year deal to 2011, paying particular regard to the 2% inflation target.

But the NUT's general secretary, Steve Sinnott, said he could not imagine the circumstances in which there could possibly be a three-year deal.

Timetable

During the conference debate a teacher from Leeds, Pat Murphy, said the NUT should aim to be part of a coalition opposing government policy, but must be prepared to go it alone if necessary.

But Mr Sinnott told journalists afterwards his emphasis would be on building a coalition with other unions.

That made the timetable uncertain, as different parts of the public sector had different pay review periods.

Work would begin after Easter on informing the NUT's own members what was happening, he said.

The TUC had called a liaison meeting for 14 May.

First stage

In view of the fact that there has not been a national teachers' pay strike for almost 40 years, he was asked how serious the threat was.

Mr Sinnott said he had been the principal author of the strike motion.

"I'm not going to put my name to making threats that I'm not prepared to carry out," he said.

The motion instructs the union's leaders to "prepare to ballot members for a national one-day strike in co-operation with other teachers' organisations and public sector unions".

This would be "the first stage" of industrial action to protect pay.

A spokesperson for the Department for Education and Skills said: "Strikes only achieve one thing - disruption to pupils' learning.

"Teaching remains one of the most respected and rewarding professions, with an 18% real terms increase in the average teacher's pay since 1997."

In the NUT debate a delegate from Lambeth in London, Sara Tomlinson, said it was now hard to find a home in her area for under �300,000 - beyond the reach of many young teachers.

"The NUT might be the first union to put its name to public sector-wide strike action, but it certainly won't be the last," she said.

'Bullying'

The conference has also condemned the increased practice of lessons being observed by school managers.

Kirklees head teacher Gill Goodsen said she was ashamed, appalled and angry at the actions of some of her colleagues, who were subjecting their teachers to repeated observations.

"At its worst it is bullying, pure and simple."

She said she did not find it necessary to check on her staff more than once a year.

"I believe I know my school," she said.

"Excessive monitoring can be seen as a sign of weakness, insecurity, fear."