During the debate in the Northern Ireland Assembly this week over same-sex marriage, it was suggested that legalising gay marriage could threaten the freedom of Catholic schools to teach the traditional view of marriage.

However, Conall McDevitt of the SDLP scoffed at this idea. He asked “Are Catholic schools teaching children about divorce?” In other words, even though divorce has been legal in the UK for years and years, Catholic schools are not being forced to teach that divorce is morally permissible. Therefore, why should we think they’ll be forced to teach that same-sex marriage is morally permissible?

But McDevitt’s analysis overlooks some crucial points.

First and most importantly, being against divorce does not usually get you labelled as a bigot. Therefore the UK’s equality legislation doesn’t come into play to anything like the same extent.

On the other hand, opposition to same-sex marriage, or adoption for that matter, is regularly classified as a form of bigotry. Essentially, for this reason Catholic adoption agencies in the UK were forced to close.

Furthermore, there is no organised lobby to condemn those who regard divorce and remarriage sinful. In the case of homosexuality, there is an extremely powerful lobby who are relentless in pursuing what they see as discrimination.

McDevitt’s retort might have seemed like a clever line at the time. But the threats to religious liberty suggested by Sammy Wilson are, unfortunately, all too real.

Indeed, he might pay heed to what Professor John Haldane had to say about this matter last Friday night when he addressed an event hosted by The Iona Institute.

Professor Haldane warned that Catholic schools in Scotland would be “vulnerable to civil and criminal action for teaching traditional Catholic teaching concerning sexual morality” should same-sex marriage be legalised there.

He said: “The upshot is that there is a very serious threat to the future of publicly supported denominational schools in Scotland.

“One can have no confidence that in 10 years time there will not be a fairly sustained and probably effective campaign to bring to an end to publicly funded Catholic schooling.”