Teaching unions have defended Estelle Morris following her intervention in the row surrounding the reinstatement of two pupils at Glyn Technology School in Surrey.

The move came after Morris said that the two boys, who are accused of leaving telephone death threats against a male teacher, should not return to the same school.

Chris Keates, deputy general secretary at the NASUWT, said the panels which determine whether pupils are readmitted should be scrapped.

"NASUWT has for years been calling for the abolition of these panels. Their procedures and composition are shrouded in mystery," she said.

"They are divorced from the school situation and they regularly reinstate violent and disruptive pupils on a technicality."

Education minister Stephen Twigg also defended Morris after she was accused of seeking to control what should be an independent process.

Whilst he said the case was "very serious" he admitted the minister had acted beyond her powers.

"I acknowledge that the secretary of state cannot direct in these individual cases, what we can do is try to use our influence and our good offices and that is what we're trying to do now," he told the BBC.

"There are thousands of these decisions made across the country every year. What we're saying is that this was a very, very extreme example and it would have been wrong for us just to have sat back and allow events to unfold.

"In the overwhelming majority of cases these decisions are made by the panels and that is that. This is not a typical case."

The shadow education secretary, Damian Green, said the minister should not have intervened.

"As ever, the government is more concerned with its image than with helping schools facing a crisis," he said.