Michael Gove has told MPs that pupil behaviour problems are a major "obstacle" to attracting the brightest into teaching.
But his comments to the Commons education select committee at the end of last year have been rejected by the Association of School and College Leaders (ASCL), which says workload and the pressure of league tables are bigger factors.
The research that Mr Gove based his statement on - a 2008 report by think- tank Policy Exchange - shows that pay is actually the greatest deterrent to teaching among students at the UK's top universities.
And Teach First, the organisation cited by ministers as an example of what can be achieved in attracting the most able into teaching, also says pay is a problem.
Asked by The TES what the biggest barriers were to getting able graduates into teaching, Teach First listed four factors, including salary, but did not mention safety or pupil behaviour.
Mr Gove raised the issue of classroom safety when he was asked by MPs last month what more could be done to achieve his central goal of improving the quality of teachers.
"We can make teachers feel safe in the classroom," he said. "One of the reasons there are many people who would think of going into teaching, who are academically gifted and enjoy being with young people, one of the reasons they resist going in is because they feel they will not be safe."
But ASCL general secretary Brian Lightman said: "That is not our perception. There are other things that put them off. The pressure of work and the accountability system would be the top two things.
On classroom safety, he said: "I really don't think it is an issue. Incidents that compromise safety in the classroom are relatively rare."
Where's the sex appeal?
The issue of classroom safety does not feature at all in the list of the biggest barriers to teaching cited by Teach First, the organisation that persuades some of the country's most able graduates to teach in the toughest schools.
Instead, Teach First cites the "those who can, do; those who can't, teach" perception of the profession and the lack of prestige compared to medicine or law. It said graduates could view teaching as "not trendy, not sexy when compared to the pull of banks and professional services" and "not glamorous" when thoughts of "rundown schools" and school dinners were compared to a tower in Canary Wharf.
Teach First also cited pay - the lack of "the big bucks that could be gained in other careers" - as a barrier.