Bruce Douglas, president of the Secondary Heads Association, who meet in Birmingham today, said: “This is a key time for our union. It is a time when we must prove that a modern school leadership can deliver the goods. But if we are to do our job, we must be given the space to work.”

Mr Douglas, who is head of a grant-maintained school in Lincolnshire, believes his union must assert the role of heads as the Government drafts its code of practice for local authorities and discusses changes to school funding.

“Schools should be part of a voluntary partnership with local authorities. I accept the system must be policed, but old-fashioned local authorities must not use their new role in promoting standards to try and run schools,” he said.

The conference will be the first opportunity for members to meet David Blunkett, as Education Secretary. It will also be John Sutton’s last before he retires as general secretary. He said he was disappointed with the Government for not giving the teaching profession proper recognition and for doing little to raise morale.

He said: “They have gone ahead with an advanced skills teacher grade many of us think will not work. We are not necessarily opposed to the idea, but could have suggested other ways forward.”

John Dunford, former SHA president, said he hopes Mr Blunkett goes home with the message that heads need support as well as pressure. He said league tables, target-setting and benchmarking were making many members jumpy.

Mr Blunkett may also be quizzed on selection. Dame Tamsyn Imison, chair of the union’s equal opportunities committee, said: “The move towards increased specialisation can be used by some schools to recruit by ability. Musically-gifted children are often academically able. My view is that it flies in the face of education for all.”

But she says funding will be the key issue. She is concerned that not all of the extra pound;850 million allocated for education reaches schools.

Also on the weekend’s billing are the other two Bs - Professor Michael Barber of the standards and effectiveness unit and Professor Tim Brighouse, Birmingham’s chief education officer.