THE Scottish Government will today announce controversial proposals on gay marriage amid an increasingly bitter split over the legislation from religious and pro-equality camps.

Details will be unveiled after a cabinet meeting, with First Minister Alex Salmond under pressure to go ahead with plans to legalise same-sex marriage amid outrage from the Catholic Church and Muslim community.

Cardinal Keith O'Brien, the leader of Scotland's Catholics, has demanded a referendum on the policy after an official consultation on gay marriage drew more than three times as many responses as the consultation on independence.

Almost 80,000 people responded to an official consultation on same-sex marriage while 26,000 have responded to the one on independence.

However, politicians and equality groups have urged the Scottish Government to "stand firm".

Scottish Labour's Social Justice Spokesperson, Drew Smith MSP, said: "This week, the SNP Government can finally make clear its intention to make progress on what is fundamentally an issue of equality.

"I had the great privilege to speak at the Glasgow Pride event, and anyone who was there would know there is real momentum in the campaign for marriage equality."

The Scottish Government has tried to reassure religious groups they would be able to opt-out of performing wedding ceremonies for same sex couples if they opposed it, but the Catholic Church has warned that churches and priests could face court action if they refused to allow same-sex ceremonies in their places of worship.

Cardinal O'Brien has authorised a plan to raise £100,000 for a campaign against same-sex marriage.

He said: "Clearly, if it is sensible to hold a referendum on independence, it is crucial we have one on marriage. It is the only way the country can move forward on this issue."

Colin Macfarlane, director of Stonewall Scotland, said the Cardinal's call for a referendum was "desperate and totally out of step with public opinion".