Gay rights campaigner Peter Tatchell says the demotion of a Christian housing manager for remarks about religious gay marriage was “excessive”.

Mr Tatchell spoke out in support of Adrian Smith, 54, who was disciplined by the Trafford Housing Trust for the remarks on his private Facebook page.

Mr Smith wrote that while the state was free to legislate for gay civil marriage, he felt that churches should not be forced to hold ceremonies.

When a colleague complained, he faced a disciplinary hearing and was found guilty of gross misconduct. He was demoted to the role of money support advisor and his salary dropped from £35,000 to £21,000.

Mr Tatchell said the trust’s actions were “excessive and disproportionate” and it should have simply warned Mr Smith about identifying himself as an employee online.

He said: “The trust was acting with good intentions in a bid to ensure equal opportunities, non-discrimination and inclusive service provision. Although its commitment to equality for lesbian and gay people is commendable, its response to Mr Smith’s remarks is excessive and disproportionate.”

Citing Mr Smith’s remarks about religious gay marriage being “an equality too far”, Mr Tatchell said: “This is not a particularly homophobic viewpoint. Adrian Smith’s opposition to churches being compelled to hold gay marriages is shared by much of the population, including many equality and human rights organisations.

“Adrian Smith reportedly made his comments in his own time on his personal Facebook page, which is not viewed by the general public. He expressed an opinion. He did not personally discriminate against anyone. There is no evidence that he has treated any of his gay housing clients adversely.

“His only possible misdemeanour is that he made his comments on a Facebook page where he identifies himself as an employee of the Trafford Housing Trust, allegedly contrary to the trust’s rules.”

Mr Tatchell added: “His opposition to religious organisations being forced to conduct same-sex marriages is shared by the Prime Minister and the Equality Minister, the gay rights group Stonewall and the entire leadership of the Church of England. If Mr Smith is guilty, then they are all guilty.”

Commenting on a news story about gay marriages in church, Mr Smith, who attends an evangelical church, wrote: “An equality too far.”

The next day, when asked by a friend if he disapproved of the move, he added: “No, not really. I don’t understand why people who don’t believe in Christ would want to get hitched in church.

“The Bible is quite specific that marriage is for men and women. If the state wants to offer civil marriages to the same sex then that is up to the state; but the state shouldn’t impose its rules on places of faith and conscience.”

Mr Smith has indicated he will sue Trafford Housing Trust for loss of earnings and breaching his human rights. He is being supported by the Christian Institute.