The Catholic Church has explained its position on trans rights - and it's singing from a very old, very homophobic hymn book. (Michael Campanella/Getty Images)

The Catholic Church has vowed to defeat gender recognition reform in Scotland to reassert the “natural instinct” of marriage between one man and one woman.

The church restated its long-standing anti-gay beliefs in a briefing paper on transgender issues, after Scotland’s first minister Nicola Sturgeon published a draft bill to simplify the country’s gender recognition rules for trans people.

Defeat trans rights to preserve ‘natural instinct’ towards straight marriage, says Catholic Church

The briefing paper, published by the Catholic Parliamentary Office of the Bishops’ Conference of Scotland, asserts that the lawmakers have no right to “redefine” the “natural law” of marriage or gender – a full five years after gay weddings began in Scotland.

The briefing states: “The Catholic Church believes that marriage is a union between one man and one woman. The determination of sex for this purpose is based on biology.”

It adds: “Redefining something as fundamental as male and female is not within the purview of government or parliamentarians.

“Like marriage, it is part of the natural law: an unchanging principle of human existence. Redefining what it means to be male or female will create confusion, upsetting the equilibrium of society and our natural instinct toward the marriage of man and woman and the flourishing of family life. ”

The briefing paper also suggests that “those who work in education, healthcare workers [and] marriage celebrants” should have the right to act based on their religious beliefs on gender.

Do stop us if this is all sounding sickeningly familiar.

The draft bill, currently being consulted on by the Scottish government, would lower the minimum age to change your legal gender from 18 to 16, and permit people to do so by making a sworn declaration – eliminating bureaucratic hurdles and the need to gain medical approval.

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The briefing paper also parroted rhetoric shopped around by anti-trans activists – as the Catholic Church expressed some newfound concern for the rights and wellbeing of children and women.

The church also claims that the reforms pose an “increased risk to the safety of women” – as opposed to, say, forcing untold numbers of people to have risky backstreet abortions or something.

It also insists that opening legal recognition to 16 and 17-year-olds “puts them on a dangerous path towards irreversible medical experimentation” while simultaneously claiming the need to seek approval from doctors “may fail to provide the necessary support for those affected by gender dysphoria.”

Speaking to Catholic outlet Crux, a church spokesperson said: “Fundamental rights must be upheld for those who do not subscribe to the idea that gender is fluid or can be wholly divorced from biological sex.

“Erosion of these rights risks the creation of a totalitarian society where free speech and even free thinking on such matters are oppressively policed by those in authority, rolling back hard won and widely cherished democratic values.”