Cardinal Keith O’Brien, leader of the Catholic church in Scotland, claims the proposals are “madness”.
Writing in the Sunday Telegraph, he accused the coalition of trying to “redefine reality”.
He continues: “Since all the legal rights of marriage are already available to homosexual couples, it is clear that this proposal is not about rights, but rather is an attempt to redefine marriage for the whole of society at the behest of a small minority of activists.
Same-sex marriage… would create a society which deliberately chooses to deprive a child of either a mother or a father.Cardinal Keith O’Brien
“Same-sex marriage would eliminate entirely in law the basic idea of a mother and a father for every child. It would create a society which deliberately chooses to deprive a child of either a mother or a father.
Earlier this week the Home Office defence the government’s plans after Tory MP Peter Bone called them “completely nuts”.
A Home Office spokesman said the government believed that “if a couple love each other” and want to commit to a life together, they should “have the option of a civil marriage, irrespective of their sexual orientation”.
We have had prejudice, discrimination and homophobia for hundreds of years. That doesn’t make it right.Harriet Harman, Labour deputy leader
Equalities minister Lynne Featherstone is due to launch a consultation on the government’s plans later this month.
Margot James, the first openly lesbian Conservative MP, criticised Cardinal O’Brien’s “apocalyptic language” and accused him of “scaremongering”.
Last October Channel 4 News reported that Mario Conti, the archbishop of Glasgow, had written to every parish urging all Catholics to oppose a change in the law, claiming that letting gay couples marry would damage social cohesion.
She told BBC1’s Andrew Marr Show the government was not “trying to force Catholic churches to perform gay marriage at all – it is purely a civil matter”.
On the same programme, Labour Deputy Leader Harriet Harman said: “We have had prejudice, discrimination and homophobia for hundreds of years That doesn’t make it right.”