England's General Teaching Council has voted against having lay members on its disciplinary panels, despite concerns over the risks of self-regulation.
The Audit Commission, the public-sector watchdog, said including a lay member on the three-person panels would allay fears that the profession was acting as its own judge and jury.
Professional self-regulation has been in the spotlight since the inquiry into the serial killer Harold Shipman. Dame Janet Smith's inquiry into the murders found that regulatory bodies such as the General Medical Council had to serve the public interest and not the interests of the profession they represented.
But the council's meeting in York this week voted narrowly by 24 votes to 23 not to change the make-up of panels.
Since its inception in 2000, the GTC has heard more than 100 disciplinary and competence cases.
Terry Bladen, a secondary teacher representative, said: "I would have great concerns about why someone from the outside world would want to come here and sit in judgement on teachers."
But Conchita Henry, of the Association of Colleges, accused council members of hypocrisy and arrogance. "What right have we got to suggest these people may not have the integrity or the intelligence that we have?" she said.
"This has become an issue because other regulatory bodies have come a cropper."
Carol Adams, the council's chief executive, said the issue would have to be revisited in the future.
The GTC also rejected the commission's call to cut its number of members from 64. However, its membership is changing: the Local Government Association will lose two of three representatives, with higher education losing one of its three. A fourth will go through the merger in 2007 of the Disability Rights Commission and Equal Opportunities Commission, which are represented individually. The four will be replaced by members from the Teacher Training Agency, parents' and governors' groups, the youth service, and the Learning and Skills Council.
* Fewer teachers want to be heads, according to a GTC study.
A National Foundation for Educational Research report found only 7 per cent want promotion, compared with 10 per cent in 2004. A quarter with less than 10 years' experience are uncertain whether to stay in teaching and nearly 25 per cent plan to retire within five years.