By Alex Stevenson
The senior Catholic whose attack on gay marriage proposals as "grotesque" attracted a media storm yesterday is refusing to back down.
Cardinal Keith O'Brien told the Today programme he believes countries which allowed same-sex marriages were "shaming themselves", a day after comparing the notion to slavery.
His remarks have been condemned by gay rights organisations and politicians, but are supported by an epetition which is approaching 100,000 signatures.
"We're taking standards... from the declaration on human rights of the UN where marriage is defined as a relationship between men and women turning it on its head," he told the Today programme.
"We're trying to redefine something which has been known and revered for centuries and making it something different."
The coalition is expected to launch its proposals on making gay marriages legal later this month.
Cardinal O'Brien said they were the "thin edge of the wedge". He denied that religious groups were seeking to maintain ownership of the word, however.
"The church doesn't own marriage, it's a natural state," he argued.
"We know natural law teaching of what marriage is as well. It is quite simply natural for a man and a woman to be together for the procreation and education of children and for their own mutual love."
Ben Summerskill of gay rights group Stonewall pointed out that gay marriages were only being sought for civil premises.
"The cardinal has a brass neck," he told the Sun.
"He leads a church which abused tens of thousands, if not hundreds of thousands of little girls and boys. If he is really concerned about the family he should address the issue of the three million children in single parent families."
Cardinal O'Brien raised rising abortion numbers as evidence that Britain's moral fibre was disintegrating. He suggested the introduction of same-sex marriages in Britain would lead to "further aberrations".
"It's time now to call a halt to what you might call progress in society," he added.
"I don't call it progress, the things that are happening nowadays... society would be degenerating even further than it has already degenerated into immorality."