The BBC Trust has upheld a complaint against a radio presenter who stood up against an anti-gay activist in an interview.

The controversy emerged in November when BBC Three Counties Radio host Iain Lee interviewed Libby Powell of Christian Concern and the Christian Legal Centre.

Christian Concern is an extreme Christian group which is strongly committed to opposing LGBT rights, speaking against equality on issues from same-sex parenting to anti-bullying campaigns, and opposing the decriminalisation of homosexuality globally.

Things turned fiery on-air between the pair while discussing the case of a prison gardener who says he was ‘persecuted’ at work, after getting a warning for telling inmates that homosexuals must repent their sexuality to please God.

In the interview, Lee asked Powell whether she was a “bigot” several times, and challenged her group’s anti-LGBT aspersions.

However, after Christian Concern encouraged its supporters to complain en masse about the interview, the BBC apologised and dropped Lee as a presenter, adding: “Iain Lee will no longer be presenting his shows on the station but we want to take this opportunity to thank him and wish him well for the future.”

In a judgement published this week, the BBC Trust upheld the complaints from the group – finding that Lee “seriously breached” impartiality.

The Trust’s report says: “The Executive informed the Trust they considered there had been a serious breach of the Editorial Guidelines and provided a written report.

“Trustees… agreed that the presenter did not show due impartiality in the conduct of two of the interviews and that their tone was unduly confrontational.

“This breach of impartiality followed occasions when other local radio presenters, while endeavouring to engage with audiences, had voiced personal opinions, in breach of the Editorial Guidelines.

“Trustees noted that the Executive was also concerned about this and had produced a face-to-face training programme for presenters and their programme teams that would be rolled out across the BBC’s local radio services in the first quarter of 2016.”

The report added: “Trustees considered that it was of the greatest importance to the BBC that its output reflected the widest range of opinion and did not stifle debate.

“They believed that the BBC’s local radio output had a critical role to play in terms of enabling the widest possible public debate and that local radio presenters had considerable leeway to be provocative to engage audiences.

“However, they considered that where presenters appeared to defend a particular stand on an issue in an inappropriately combative manner the effect was not to broaden debate but was likely to be the opposite – as potential callers might be less likely to contact a radio station if they felt they would not receive a fair hearing.

“The Committee considered this was a serious breach of the Editorial Guidelines for Impartiality.”

The Trust’s report comes despite broadcast watchdog Ofcom rejecting all complaints against Lee.

Mr Lee is now a presenter on commercial station TalkRadio.

Christian Concern has previously claimed that anti-bullying campaigns are playing into the hands of a gay “Trojan Horse” attempting to promote gay sex to children.

The group often exhibits objectively bigoted views, claiming Stonewall is an “ideological propaganda machine” attacking families.

Anti-LGBT CEO Andrea Williams, who has had involvement with ‘gay cure’ events in the past – also affirms that gay couples are “selfish” for having children.

The group has also backed laws criminalising gay sex in other countries. Speaking at a conference in Jamaica in support of the country’s buggery law, Williams cited Tom Daley in claiming that homosexuality can be “caused” by a “lack of the father” and “sometimes a level of abuse”.