The chair of school inspection watchdog Ofsted accused headteachers and boards of governors today of lacking the "moral courage" needed to deal with under-performing teachers.
Zenna Atkins said school leaders should be ready to "bite the bullet" and risk employment tribunals by getting rid of teachers who are failing their pupils. It was a "myth" that bad teachers could not be sacked, she said.
Ms Atkins sparked controversy over the weekend after she was quoted in the Sunday Times as saying that "every school should have a useless teacher".
In an interview on the BBC Radio 4 Today programme this morning, she did not deny making the remark, and said she believed it was inevitable that every school would have a useless teacher and that it was "not always a disaster" for the children in his or her class.
She said: "I think it is inevitable that every school will at some point will have a useless teacher. If you look at any population of a workforce, there are people who are under-performing and that's often a significant percentage - up to 10% of people under-performing.
"It is inevitable, and it is not always a disaster, because children go to school to learn how to be in society.
"I don't think they should have a useless teacher, but I think at some point it is inevitable that they will have."
Ms Atkins added: "The important thing is that the leadership is able to deal with these teachers and to move them on where necessary.
"We seem to have a persistent lack of moral courage in dealing with poorly-performing teachers and poorly-performing teaching standards.
"I think there is a lot of myth around the fact that it is impossible to get rid of teachers and it is too unionised.
"Actually unions have no interest in poorly-performing teachers remaining in schools. I think that's a myth and people are very worried about litigation and very scared about being seen to do the wrong thing and ending up in employment tribunals.
"That's not good enough for our children.
"It is much better to end up in an employment tribunal and do the right thing by your kids than to have left a bad teacher - particularly in primary school - teaching children when they are very vulnerable."
Ms Atkins said today's generation of teachers were "far better equipped to deal with the modern teaching environment" than ever before.
But she added: "The issue is almost an underbelly of poorly- performing teachers who are just being accepted. People don't seem to have the strategies to move them on and move them out.
"Everybody knows who they are in a school - the children know as young as eight, they tell you which are the really good teachers and which are under-performing.
"The key thing here is what can leadership do to move them on. Headteachers and governing bodies have a responsibility to tackle that and do something about it, from performance management and enhancing teachers' skills to biting the bullet and saying 'You are going to leave the school because it isn't good enough for my pupils'."Reuse content