Scottish ministers are expected to discuss legalizing same-sex marriage in the country when the cabinet meets today (17 July).

Pro-gay marriage ministers from the Scottish National Party will announce legislation following the results of a consultation this week, with a finalized bill likely to appear by 2013.

Unlike England and Wales’ proposals, it is planned Scottish churches will be able to bless gay unions but would be free to opt-out.

Gay rights groups including Stonewall Scotland, the Equality Network and Amnesty International have also fought to push Scotland's parliament to pass the legislation.

However, despite widespread support for a change in the law, there has been fierce opposition from some religious leaders and clerics.

Cardinal Keith O'Brien, Britain’s most senior Catholic, yesterday (16 July) demanded a referendum on same-sex marriage in a last-ditch effort to delay the decision.

O'Brien has declared war on the proposed marriage equality bill which he described as ‘madness’ and likened to 'slavery'.

The Catholic Church says it will spend an additional £100,000 ($155,000 €127,000) on an advertizing campaign against the plans, on top of the £50,000 ($78,000 €64,000) it has already spent against marriage equality in Scotland.

But some religious groups favor the bill, with churches such as the Quakers saying they would be happy to conduct weddings.

The Faith in Marriage group, which includes the United Reformed Church,  Buddhists and the Pagan Federation, was formed in April to urge politicians to lift the ban on religious same-sex marriages in Scotland.

The SNP has been the main party pushing for gay marriage legislation in Scotland, with Jim Eadie MSP urging the Scottish government to 'Stand firm, hold your nerve.'