The public humiliation of teachers at disciplinary hearings held by the General Teaching Council for Wales must stop, a union leader said this week.

Rex Phillips, Wales organiser of the NASUWT teachers’ union, said opening the doors to the press and public was “tantamount to placing teachers in stocks”.

He spoke out after a female teacher was found guilty of unacceptable professional conduct for having sex with a sixth-form student. Mother-of-two Abby Pippin, former head of chemistry at Bridgend’s Bryntirion Comprehensive, admitted the offence, but denied having sex with the boy.

Alwyn Thomas, her head, told the hearing that rumours had started circulating in 2006 that Ms Pippin and the sixth former (Pupil A) were having a relationship after they were spotted in a supermarket.

After many meetings with Ms Pippin, he said she admitted there had been an “inappropriate relationship” that included frequent phone calls, holding hands and kissing.

Ms Pippin was sacked for gross misconduct after two teachers, Beverly Hill and Rhaea Mortimer-Griffiths, told Mr Thomas that she admitted to them she had sex with the pupil when he turned 18.

But Ms Pippin, who did not attend the hearing, claimed the pupil was “obsessed” with her, and that she had tried to help him when he became depressed and felt suicidal.

She said she had shown poor judgment. The case was referred to the teacher misconduct team run by the Westminster government. It reviewed the evidence and decided that allegations of a sexual relationship could not be upheld.

But the GTCW panel decided that the allegations were true on the balance of probability and gave Ms Pippin a three-and-a-half-year conditional registration order.

Mr Phillips said the panel’s verdict was “ill-considered”. He accused the teachers who gave evidence against Ms Pippin of trying to besmirch her reputation, which he said was reprehensible behaviour.

Referring to the committee’s decision to hold the hearing in public, a GTCW spokesperson said that although Ms Pippin might find it distressing, this did not outweigh the legitimate public interest in these proceedings. There was also insufficient evidence that any third party might be adversely affected.