The schools secretary has pledged new protection for teachers from the threat of cyber bullying.

Ed Balls told the annual conference of the NASUWT union in Birmingham on Wednesday that a "cyber bullying taskforce" for England will look at new ways of tackling the problem of staff being harassed online by pupils.

Balls said he wants the matter to be a "serious disciplinary offence".

"Bullying is never acceptable, and we will do all we can to prevent it in all its forms," he said.

"The law requires headteachers to take action to prevent all forms of bullying.

"It also gives school staff statutory power to punish bullying, whether that occurs in or out of school.

"We already give schools advice on the practical measures they can take to tackle bullying, including guidance on dealing with cyber bullying. But I want to go further."

However shadow children's secretary Michael Gove said: "The government is adding more bureaucracy to the process teachers have to go through to exclude disruptive pupils.

"What headteachers need is the power to exclude troublemakers without having their decision overridden.

"With pupils excluded for making death threats being allowed back into schools, and the units for excluded pupils at breaking point, no one is going to take this announcement seriously."