BRITAIN's most senior Catholic has been branded "grossly offensive" and "stuck in a time warp" by a Bristol MP in the growing row over gay marriage.
Stephen Williams said he was "astounded" by comments from Cardinal Keith O'Brien, who suggested that same-sex unions were as immoral as slavery.
David Cameron has publicly backed a law change to allow gay marriage, and the government is to launch a consultation later this month.
As well as the criticism from Cardinal O'Brien, who is the leader of the Catholic Church in Scotland, John Sentamu, Archbishop of York recently said ministers would be "dictators" if they tried to change the law.
Bristol West MP Mr Williams, who is gay, said: "Whether the Roman Catholic Church or the Church of England wish to introduce same-sex marriages is entirely a matter for them. This is why I find the outbursts by Cardinal O'Brien and Archbishop Sentamu so utterly bizarre. The state is not proposing any change to the marriage rites and ceremonies performed in their churches."
"Cardinal O'Brien's choice of language was also grossly offensive. To claim that the granting of a right to same sex couples to enter into a civil marriage would be a 'grotesque subversion of a universally-accepted human right' is astounding. He clearly believes that gay people are outside the human family, deserving of lesser rights. His analogy of a re-introduction of slavery without the obligation on each of us to own a slave is utterly baseless and again grossly offensive."
"Cardinal O'Brien's mind seems to be stuck in a time warp, perhaps in pre-1834 Britain when slavery existed and women had few rights against their husbands."
Allowing gay marriage would bring happiness to people without infringing the rights of others, he said, adding that it would make the UK a "world leader" in human rights and equality.
The leader of Catholics in England and Wales, Archbishop of Westminster, the Most Rev Vincent Nichols, has said that extending marriage to same-sex couples would strip the union of its "distinctive nature" and remove the intention of procreation.
His comments come in a letter due to be read from the pulpit in 2,500 churches during Mass this Sunday.