The Catholic Church in Scotland has intensified its attacks on proposals to give gay couples the right to marry.

Bishop of Paisley Philip Tartaglia, who is expected to become the next Archbishop of Glasgow when Mario Conti steps down, said marriage equality would be “an act of cultural vandalism”.

Yesterday, the leader of the Scottish Catholic Church, Cardinal Keith O’Brien, said the change would be a “grotesque subversion of a universally accepted human right” and that gay parents cannot adequately bring up a child.

The Scottish government opened a consultation on the issue last week. Ministers say they “tend towards the view that same sex marriage should be introduced” but no formal position has yet been taken.

Ministers have stressed that churches would not be forced to hold gay marriage ceremonies.

In a submission to the 14-week consultation, Bishop Tartaglia said marriage should not be an equality issue because gay couples cannot have children.

He added that the government does not deserve the “trust” of Catholics or the nation.

The bishop wrote: “Marriage has always existed in order to bring men and women together so that the children born of those unions will have a mother and a father. For that reason, same sex unions cannot fulfil the nature and purpose of marriage. Marriage, therefore, should not be treated as an equality issue.

“A government which favours and allows for same sex ‘marriage’ does wrong. It fails in its duty to society. It undermines the common good. It commits an act of cultural vandalism. Such a government does not deserve the trust which the nation, and including many in the Catholic community, has shown in it.”

He added that governments “do not have the authority to say what marriage is or to change its nature or to decree that people of the same sex can marry”.

Cardinal Keith O’Brien wrote in the Scottish Mail on Sunday that gay parenting “means that our society deliberately chooses to deprive a child of either a mother or a father”.

He added: “All children deserve to begin life with a mother and father, the evidence in favour of the stability and well being which this provides is overwhelming and unequivocal. It cannot be provided by a same sex couple however well intentioned they may be.”

Last week, Mario Conti, the Archbishop of Glasgow, said that allowing gay marriage would be “foolish” and render marriage “meaningless”.

Despite church opposition, the 2010 Scottish Social Attitudes Survey, found that 61 per cent of people believe gays and lesbians should have the right to marry.

Scotland has allowed gay couples to have civil partnerships since 2005, which grant all the rights of marriage.

But gay rights campaigners say the two-tier system is discriminatory and the unions do not have the same status.