By Justin Parkinson BBC News Online education staff, in Bournemouth

Schools should show "zero tolerance" to pupils and parents who assault teachers, an education minister says.

Stephen Twigg said: "It's important that incidents are reported and sometimes result in prosecutions."

The comments, at the Association of Teachers and Lecturers' annual conference in Bournemouth, come after the union voted on Tuesday to push for greater staff protection.

A survey by the General Teaching Council of England last year found one third of teachers expected to leave the profession within three years. Bad pupil behaviour was a reason cited by many.

'Need to deal with it'

Mr Twigg said: "It can be a tricky issue for schools, as they might think reporting it could have an effect on recruitment.

"It's like bullying. There needs to be an honest acceptance that it is happening before we can deal with it."

Mr Twigg also told the conference he was keen that the number of "extended" schools, which offer services such as healthcare and social workers, grew.

To encourage more family involvement in education, he proposed parents meeting just form tutors at secondary school open evenings, rather than "10 or so teachers, one for each subject", as is currently the case.

Mr Twigg cited the example of Hillcrest School in Dudley, where attendance at parents' evenings had increased from 25% to 75% following this.

He said: "It is absolutely vital that schools do all they can to get parents more involved in their child's education.

"Doing so can have a significant impact on how well they do."

Mr Twigg added: "Clearly there are parents who had bad experiences of education themselves.

"For some, there will be a fear of involving themselves with the schools system."

Mr Twigg refused calls from some ATL delegates for national testing of primary school pupils to be abolished.

He denied the government wanted a "one-size-fits-all" model of education.

Instead, he said, broader standards could be maintained in a way "that realises and encourages the community to be involved, so there is flexibility at the local level.

"First, we need to get the big structural changes right."

The ATL conference ends on Thursday.