David Cameron is facing fresh pressure from the leader of the Catholic Church in Scotland over plans for gay marriage.

Cardinal Keith O'Brien has claimed the proposals are "madness", and accused the coalition of trying to "redefine reality".

O'Brien said: "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 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.

A Home Office spokeswoman 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".