The leaders of Scotland’s four opposition parties pledged their support for equal marriage rights for gay couples yesterday.

The heads of the Scottish Labour, Conservative, Liberal Democrat and Green parties backed the Equal Marriage Pledge, which aims to lift the ban on gay marriage and straight civil partnerships in Scotland.

Johann Lamont MSP, Ruth Davidson MSP, Willie Rennie MSP and Patrick Harvie MSP jointly signed the Equality Network document at Holyrood yesterday afternoon.

The Scottish Parliament of 129 seats is made up of 69 Scottish National Party members and opposition, 59 opposition party members and one independent MSP.

Following the move, over 400 people attended an Equality Network reception in the Scottish Parliament.

Tom French, Policy Coordinator for the Equality Network, said: “We are delighted that leading politicians from across the political spectrum have united for Equal Marriage. We know that a majority of Scots back full equality for lesbian, gay, bisexual and transgender people, as highlighted by the huge turnout at tonight’s reception.

“We agree with Alex Salmond’s ambition to make Scotland a progressive beacon. The principles of equality, and freedom of religion, are surely integral to that. With the support of all opposition leaders, and a clear majority of the public, the Scottish Government now have all the backing they need to move forward with legislation.”

Launching the consultation on gay marriage last year, Scotland’s Deputy First Minister Nicola Sturgeon said the SNP government was minded towards equal marriage.

In April, First Minister Alex Salmond, announced his personal support for same-sex marriage, saying: “If a denomination is prepared to accept gay marriage then I’m in favour of it, yes. My personal feeling would be to tend towards it. But we’ll put it out to consultation.”

The Equality Network has said it recognises the government may not be able to sign the pledge until consultation results are announced in the spring.

Johann Lamont MSP, Leader of the Scottish Labour Party, said: “I believe that the public witness and celebration of same-sex relationships afforded by civil partnerships and the legal rights created have played an important role in changing attitudes to LGBT people. I support the campaign for Equal Marriage and legislation which would allow religious bodies to conduct same-sex marriages should they wish to do so.”

Ruth Davidson MSP, Leader of the Scottish Conservative Party, said: “I support the Equality Network’s Equal Marriage campaign. It seeks a more equal society while recognising that religious organisations which do not wish to carry out ceremonies should not be compelled to do so. The Scottish Government will bring forward legislation on gay marriage in this parliament and I want to ensure we have a workable way of advancing this issue for the people of Scotland.”

Willie Rennie MSP, Leader of the Scottish Liberal Democrats, said; “I want Scotland to be one of the most fair and progressive places in the world. Extending marriage equality to all is a really important part of that. The Equality Network should be congratulated on the fantastic job they have done highlighting the importance of this campaign. I am looking forward to working constructively with the all the groups involved who want to see this change in Scotland as we enter the next stage of the debate.”

Patrick Harvie MSP, Leader of the Scottish Green Party, said; “It’s really encouraging to see so much support for Equal Marriage both inside Parliament and outside, and all that’s needed is for the Government to come forward with the legislation.

“I’m convinced that when MSPs have the chance to vote on this, Scotland will once again set the pace of change for the rest of the UK by backing equality for same-sex couples. This is a vital signal about the kind of progressive society that Scotland wants to be in the 21st century.”

The Scottish Government public consultation on same-sex marriage closed on the 9 Dec, attracting over 50,000 responses. The consultation responses are currently being analysed and the Government is expected to make a decision on whether to take forward legislation soon.

Opinion polls suggest most Scots support the move. The Scottish Social Attitudes Survey 2010 indicated 61% support and 19% opposition to marriage equality.