Chris Woodhead said he wanted to silence the "tiny but vocal minority of critics" who were defending vested interests in the profession. He published a Mori poll of 1,260 primary schools showing that four out of five were happy with their inspection by the Office for Standards in Education (Ofsted).
But an argument broke out as Mr Woodhead accused a leading headteacher of "peddling disinformation" by claiming inspectors had a secret quota for the number of failing schools.
Mr Woodhead released the Mori survey after the National Union of Teachers produced its own poll saying that fewer than one in five schools believed inspection led to an improvement in standards.
The Ofsted poll found three-quarters of schools felt feedback from inspectors provided a helpful agenda for improving standards; 82 per cent found school reports fair and accurate. The poll also found 35 per cent of schools believed the benefits of inspection outweighed detrimental effects although 27 per cent thought the opposite. Mr Woodhead said the poll "paints a picture I can recognise from all my visits to schools and meetings with teachers and heads".
He dismissed the NUT survey as "seriously flawed", saying: "The vast majority of headteachers believe their inspections to be rigorous and professional and contribute to school improvement. The teaching unions are in the business of protecting the interests of their members... Ofsted's primary audience is the public, parents and children. I don't think unions are [best] protecting their members in this way. The image and the status of the teaching profession will rise: one, when the general public sees that the teaching profession is prepared to accept the kind of accountability that other professions face; and two, when standards rise."
He blamed some heads for adding to the stress of inspection but added: "In part it is down to the demonisation of Ofsted by those who should know better. Do we as a nation believe our schools should be accountable? My answer is yes, certainly. [Tony] Blair and [David] Blunkett's answer is yes."
The NUT study is the latest in a number of claims and counter-claims about Ofsted and Mr Woodhead. In autumn the Commons Education and Employment Committee began an investigation into its work.
Since being appointed four years ago, Mr Woodhead has inspired hatred and admiration. Mention of his name brings boos and hisses at teacher conferences. The battle is not just about personalities but the proportions of stick and carrot to use in improving schools.
A psychologist yesterday blamed Mr Woodhead's style for teachers' response to him. Chris Kyriacous, an educational psychologist at York University, said: "He has a confrontational style. As a manager it is bad psychology to stress the negative and it does not help to raise standards."
In February, Mr Woodhead accused three professors of education of being "at the heart of darkness" over failing pupil performance. They said he had misrepresented their views. He also attacked academics for wasting pounds 60m a year on research of "dubious quality and value".
In March, Peter Mortimore, of London University's Institute of Education, summoned a meeting of academics who demanded a review of teacher training inspections.
The National Association of Head Teachers told the select committee one- quarter of heads said staff had been awarded grades during inspections for lessons they had not taught.
Yesterday, Mr Woodhead attacked Liz Paver, past president of the National Association of Head Teachers, who said inspectors set out to fail 2 per cent of schools. She said: "In its first year of inspecting secondary schools, Ofsted had to invent a new category of `nearly failing' schools, because it couldn't come up with enough that were failing." Mr Woodhead said her comments were "dangerous and mischievous nonsense".
Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, said: "Chris Woodhead is proud that 80 per cent of those who responded judged the inspections `satisfactory' but when exactly the same percentage of schools and lessons were found `satisfactory' by Ofsted, the result was a devastating criticism by Mr Woodhead of the overall performance of the system and of teachers."
`An element of threat is not necessarily a bad thing. I personally respond to threats'
- Chris Woodhead, Chief Inspector of Schools, on his appointment
`The criticism of Ofsted is that there is a lot of polemic in your reports but that this is not backed up by evidence'
- Margaret Hodge MP, Junior Schools Minister
`The Chief Inspector has a long way to go to recapture teachers' confidence. My advice to him is to spin less and listen more'
- Doug McAvoy, general Secretary of the NUTReuse content