The General Secretary of the National Association of Head Teachers, David Hart, said the move was "absolutely outrageous".

Under government proposals, all schools in England must set targets for their results from the year 2000. It is a way of trying to achieve the national targets on which Education Secretary David Blunkett has staked his future in the job.

He has promised that, by the next election, the proportion of 11-year-olds having results appropriate to their age will go up by specific amounts and that 16-year-olds will be doing better in their GCSE exams.

With effect from next September each of the 150 education authorities must have in place local development plans - approved by the education secretary - explaining how their schools are contributing to these national goals.

'Insufficiently challenging'

The plans will list the targets set by each school, but the authorities cannot force the schools to set themselves higher targets than they feel comfortable with, so it appears some arm twisting is going on.

Government sources have confirmed that authorities which believe some schools have set "insufficiently challenging" targets will be encouraged to identify them.

"Schools are responsible for setting and delivering their targets, but as part of the local debate local education authorities are able to say where they believe some schools have not set targets which are sufficiently challenging," one source said.

"This information will be published in education development plans, and I am sure local newspapers will look at that information."

Mr Hart said: "This is clear evidence of attempts by the government and local education authorities to get schools to sign up to targets that are unreasonable.

"This is bound to damage relationships between schools and authorities and will bring the government's own targets into disrepute. There has to be room for professional disagreement about what targets are appropriate."