The book argues that while black teachers are more likely publicly to reprimand children than their white colleagues, they are also more willing to praise individual students in front of their classmates.

Author Dr Christine Callender, a senior lecturer in education at Kingston University, says: “This teaching style of openly praising and blaming is common in African and Caribbean cultures. Black children grow up with this sort of discipline at home, so they respond to it.”

A former secondary school teacher, Dr Callender was often accused by colleagues of being too strict. She said: “The first time it happened I was totally bemused. The way I saw it my attitude was just fine; it was others who were laissez-faire.”

The suggestion that black teachers use different methods to white teachers appears to be a sensitive one. All of the teachers who took part in the research were willing to comment on the book’s findings - however, each one was denied permission by their head or local authority.

One head who prevented a black member of staff from speaking publicly explained: “You have to understand how sensitive this is in an inner-city school. What is this book saying? That black teachers are better? Black kids should only be taught by black teachers? Promoting this kind of research can lead to allegations of inverted racism and cause difficulties with parents and governors, both black and white.”

Dr Callender is “flabbergasted” at that response: “I’m not saying anything controversial. I don’t say black teachers are better, just that they do things a particular way. And that way is usually supportive and empowering to black children. Although I do appreciate the hesitancy many educationists feel when publicly discussing race issues. No one wants to say the wrong thing.”

Trevor Gordon is the head of the equality service at Lambeth College in south London. He agrees with the book: “We know strong discipline works with black kids, but I for one am frequently told that I’m too hard. I find it insulting to be told how to handle children from my own race, especially when I see them responding and learning.”

Last year 872 black undergraduates started teacher-training courses, although the number of working black teachers is unknown. Next month the Teacher Training Agency and the Commission for Racial Equality are holding joint seminars to encourage the recruitment of ethnic-minority teachers.

Phil Barnett, CRE principal officer, says: “The lack of figures is a scandal in itself, but we do know there is an urgent need for more teachers from all ethnic minorities because those teachers make valuable role models. That’s nothing new. But then, aren’t black teachers good role models for white children too?” Education for Empowerment by Dr Christine Callender is available from Trentham Books Ltd, Westview Hse, 734 London Rd, Oakhill, Stoke-on-Trent, ST4 5NP, and costs Pounds 14.95