Stefan Simms, for instance, the pony-tailed head of physics and Socialist Workers’ Party member whose photograph appeared in almost every newspaper article on “classroom militants”, was defended vigorously by Stephen Armstrong, his headteacher at Wembley High School in the London Borough of Brent.

Mr Armstrong suggested that the incident involving Mr Blunkett had been “blown up out of all proportion” and that it was Mr Simms’ hairstyle rather than his actions that attracted the attentions of the press. “It’s slightly strange that he was picked out and received such extensive coverage when none of the evidence that I have received suggests that he played a more prominent role than anyone else,” he said.

Mr Simms, who is Wembley High School’s NUT representative, was interviewed informally about the affair by the head and the chair of governors at the end of last week. “On the basis of the evidence I have received through the media and eyewitness accounts, there are no grounds for any disciplinary action, ” said Mr Armstrong. “Mr Simms is a hardworking and dedicated teacher who has been coming into school over the holidays giving extra classes. He has the confidence and respect of students and staff.”

Mr Simms was appointed by Mr Armstrong in September 1993. “Yes, I did know he was a member of the SWP,” said Mr Armstrong, “but I’m confident that his personal political views don’t affect his performance as a teacher. He has however expressed regret that the way his actions have been represented may have brought the good name of Wembley High into disrepute.”

Asked whether he could honestly say he was surprised by the way the media seized on the demonstration and used it to beat the whole of the teaching profession, Mr Armstrong admitted that “it was bad tactics; if I subscribed to the particular set of views that the demonstrators did, I would not regard their strategy as a sensible one but... Mr Blunkett is a seasoned politician and for him to be shouted at is not a novel experience.”

Mr Armstrong, a former NUT member, said that he did not agree with the NUT general secretary Doug McAvoy that militant infiltrators were packing union meetings and filling the vacuum left by moderate members too burdened by work to afford the time. “The proof will come when the union is balloted on strike action, but at a local level it is not my impression that hardworking teachers do not go to union meetings... when issues are important they will find the time.”

Fran Crowhurst, the deputy head of humanities at Crofton Secondary School in Lewisham, was the most visibly angry of the demonstrators surrounding Mr Blunkett. She returned to school to teach as usual on Monday. Enquiries to her school on the first day of term were being diverted to Lewisham Council’s press office, which issued a formal statement: “Ms Fran Crowhurst met with the head Miss Anne Carhart this morning (Monday). Ms Crowhurst apologised to her for the effect that the adverse publicity had on the school. The head accepted that apology.” The statement quoted the chair of governors, Jim Stephenson, who said: “I’m entirely satisfied with the actions of the head. I will be writing to Mr Blunkett regretting the incident.”

Eddie Parkinson, head of history at Kenton secondary school in Newcastle, an official observer at the conference, was identified by some papers as the person who kicked at the door of the office in which the Mr Blunkett was temporarily imprisoned. His head, Mike Gibbons, said that he had just conducted a “long and detailed interview” with Mr Parkinson, and although no decision had been made he sounded supportive of his teacher. “We hadn’t had a chance to hear his version of events before this morning... he’s a very good teacher of history.

“It’s important that the governors have an objective version of what happened... we’ve got to strike a balance between an individual’s right to be part of something and the reputation of the school.” Mr Gibbons was emphatic that Mr Parkinson’s involvement with the SWP had no influence on the way he taught history.

The principal of Josiah Mason sixth-form college in Birmingham where demonstrator Keith McKenna teaches sociology, echoed other heads in questioning why McKenna had been singled out by the press. Nevertheless, the teachers’ role is being investigated under college disciplinary procedures.

The NUT’s new president, John Bills, said at the conference that he had been deluged with letters from delegates about the Blunkett incident. Some called on the union to protect the demonstrators from a media “witchhunt”, while others asked the NUT to give advice to members on how to proceed with disciplinary action against the demonstrators named in the press.

Mr Bills’ response was that any action either on behalf of or against members was in the hands of the members’ local associations.