Mr Watson is a prominent opponent of Scott Rennie, an openly gay minister whose appointment to a parish church last year has caused divisions. Mr Rennie, a divorced father of one, lives with his partner, David, and has the support of his Aberdeen Presbytery. The Church of Scotland is due to debate his appointment at its General Assembly next week after a petition was signed by almost a third of ministers pushing for all gays to be banned from the pulpit.

A motion has been lodged urging the Church not to "train, ordain, admit, readmit, induct or introduce to any ministry of the church anyone involved in a sexual relationship outside of marriage between a man and woman".

The row replicates the dispute within the Anglican Church about the ordination of gays. Anglican conservatives base their opposition to gay people on Bible texts that condemn homosexuality, although liberal members argue that many traditional teachings in the Bible, such as severe punishments for adultery, were no longer observed literally.

The strident position taken by Mr Watson's Forward Together organisation has provoked both condemnation and support from Scotland's religious community. The Rev Kenneth MacKenzie, the minister at Crathie Kirk, near Balmoral, which is attended by the Queen, said that he was disappointed that Mr Rennie's sexuality had become an issue but warned that a schism would occur if his appointment was confirmed.

"Life in the Church will never be the same again and my fear is that a sizeable minority of the clergy, and perhaps a majority of its people, may consider leaving the church, causing a rift felt in every parish."

Mr Watson posted on his blog last night a sermon he delivered on Sunday at Kirkmuirhill Church in Lanark, in which he invoked the failure of the French Army to stand up to the Nazi annexation of the Rhineland in 1938. "[Hitler] guessed correctly that the French had no stomach for a fight. If only they had, then the tragedy of a Second World War might have been avoided," Mr Watson said.

In the following 3,500 words, he invoked Athanasius, the Bishop of Alexandria, St Augustine, Martin Luther, John Calvin, John Knox and the Apostle Paul as he reached his rousing climax. "To claim that the homosexual lifestyle is worthy of a child of God; to demand that a same-sex partnership be recognised as on a footing with marriage; to commend such a lifestyle to others is to deny that Jesus Christ is our only Sovereign and Lord. It is to turn the grace of God into a licence for immorality," he said.

"Such people will not inherit the kingdom of God (1Cor.6:10). And therefore they must be resisted . . . Let me assure you, neither I nor like-minded minsters enjoy conflict . . . But have we learned nothing from history? Remember Hitler and the retaking of the Rhineland. He got away with it. No one stopped him. So next it was Austria, then Czechoslovakia, and then Poland and only then world war."

The sermon was greeted with outrage and disbelief by people inside and outside the Church of Scotland. Some observers questioned whether Mr Watson had infringed legislation on sexual equality. The Rev Peter Macdonald, the leader elect of the Iona Community and minister of St George's West, Edinburgh, said that he had found it deeply disturbing.

The Rev Lindsay Biddle, chaplain of Affirmation Scotland, a pro-gay group, said: "If you don't like homosexuals, then get on with it - but don't use the Bible to justify opinions."

Mr Watson defiantly defended his sermon last night. "There is no doubt that there is a conflict," he said. "I was trying to explain why I am engaged in this. People say to me, 'This is not a hill to die on', but I think it is a fight worth fighting.

"Evangelicals seek to defend the historic and orthodox Christian faith. If we don't what are we? I am a man of convictions."

END