The Chief Inspector of Schools in England, Chris Woodhead, has been criticised by teachers' leaders for urging schools to teach absolute moral rules.

In an article in the Church Times, published on Friday, Mr Woodhead attacked moral "relativists" who said that "because any definition of right action is dependent on individual situations, it is simplistic for schools to promote a set of absolute values".

He said: "We accept values as ultimate ideals to which we aspire, while recognising that we often fall short of that aspiration.

"We all experience situations where it is not possible to act in accordance with our values; perhaps when two or more of our fundamental principles are in opposition.

"The fact that there will always be exceptions does not excuse us from teaching young people the rule, just as we distinguish between regular and irregular verbs."

His comments have angered head teachers' unions, who believe Mr Woodhead should "not get involved in this area".

Mr Woodhead was also criticised in the light of revelations last year that he left his wife more than 20 years ago for a student he taught as a sixth former.

The head of the Office for Standards in Education (Ofsted) has denied claims by his ex-wife that the affair began while Amanda Johnston was still his pupil at Gordano School near Bristol.

But Peter Smith, General Secretary of the Association of Teachers and Lecturers (ATL), asked whether it was wise for Mr Woodhead to involve himself in public debate, bearing in mind the controversy over his own private life.

In the article, Mr Woodhead said that most school rules led to few moral dilemmas over issues like bullying, theft, lying, verbal abuse or the use of violence.

But he said that "other issues experienced by older pupils outside and beyond their school life are less susceptible to prescription; for example abortion and drug abuse".

"On these matters schools provide pupils with essential knowledge often not available to them elsewhere. They also teach pupils the skills ... for making moral decisions themselves."

Mr Woodhead's comments follow his intervention in the debate over Section 28 of the Local Government Act, which prevents local authorities from promoting homosexuality.

As the government attempted to scrap the controversial clause against opposition in the House of Lords, Mr Woodhead said there was no evidence it had prevented schools taking action against homophobic bullying.

'Dangerous'

David Hart, General Secretary of the National Association of Head Teachers (NAHT), said: "The chief inspector is increasingly tending to discuss matters which are outside the remit of Ofsted. I think it is dangerous for Mr Woodhead to get involved in what are clearly deep political waters."

John Dunford, General Secretary of the Secondary Heads Association (SHA), said: "I think it is unwise for the chief inspector to tread in this area.

"In a society which is increasingly unsure about its values, schools are beacons of clarity in guiding the lives of young people.

"Ofsted's inspectors repeatedly praise schools for the work they do in this area. Schools do not need to be lectured on this subject, particularly by the chief inspector."