The Ofsted school inspection system is "the equivalent of the Spanish inquisition" and should be replaced, says a head teachers' leader.

Mick Brookes, the incoming president of the National Association of Head Teachers, plans to tell the association's annual conference on Tuesday that the inspection regime is inaccurate, unfair and should be replaced.

Several heads at the conference have also raised serious doubts over the competence of some inspectors.

Some complained inspectors seemed to arrive with their minds already made up and only sought evidence fitting a preconceived verdict.

It's the equivalent of the Spanish inquisition and I think we've grown beyond that

Mick Brookes, president, National Association of Head Teachers

"It's causing schools an awful lot of stress, worry, anxiety, and every now and then you see schools are being pasted because they have had a difficult experience," Mr Brookes is expected to say.

'Out of touch'

"It doesn't do them any good, it certainly doesn't do their pupils any good, it's the equivalent of the Spanish inquisition and I think we've grown beyond that."

Chief inspector Chris Woodhead believes incompetent teachers should be weeded out

One head teacher, who wished to remain anonymous, said inspectors failed to report on some lessons yet reported on others where the teacher had not been observed.

"Schools are living in a climate of fear," she added.

Ofsted labelled Lordswood Girls' School in Birmingham "outstanding" but the school's head teacher, Jane Hattatt, still criticised the inspection team, saying most were retired and out of touch.

"I raised concerns because some did seem a little out of touch and their first-hand experience was rather some years ago," she said.

Contract workers

Alan Sutton, whose Bristol primary school was inspected last year, said some inspectors seemed to have drawn their conclusions before they arrived.

"The chair of our finance committee was asked to have an interview with one of the inspectors", he said.

"He went into the room and prepared to have an honest and frank and open discussion. The inspector said 'I know what I want to write in the report, I just want you to confirm it.'"

The inspector concluded the school was not delivering value for money.

Inspectors are self-employed and work short-term for companies who win inspection contracts through competitive tenders to Ofsted.

Robert Isaac of the Institute of Registered Inspectors estimates market forces have driven earnings down to a maximum of �36,000 per year.

Demanding role

"That has resulted in a steady loss of good inspectors from the system," he said.

Even Ofsted's fiercest critics admit most inspectors are professional and competent.

But many teachers believe Ofsted should apply the same strict standards to inspectors that chief inspector Chris Woodhead insists teachers satisfy, by weeding out the incompetent minority.