Same-sex marriage set to be legalised in Scotland as majority of MSPs say they will back Bill despite massive public opposition 86 out of 127 politicians in Holyrood say they will vote to pass legislation Ten said they remained undecided and 20 refused to reveal their opinion Consultation revealed two-thirds of respondents were against plans By Michael Blackley and Stephen Johns Scotland is to join the rest of the UK by agreeing to legalise gay marriage later this week. The Scottish Parliament's 128 MSPs will disregard massive opposition to the radical plan by voting on Wednesday to allow same-sex couples to marry. The issue has already humiliated David Cameron, with 133 of his Tory MPs trying voting against the proposals in the House of Commons earlier this year. Controversial: Politicians in Scotland are disregarding public opposition by backing same-sex marriage Now Scotland's First Minister Alex Salmond - a passionate champion of same-sex marriage - will also face a rebellion on the issue, with one of his Ministers revealing he will vote against the plans, as well as a clutch of SNP backbenchers. But a survey of all MSPs by the Mail on Sunday has revealed that an overwhelming majority of MSPs will back the proposals when they vote on the issue for the first time on Wednesday evening. Although the Bill will then be subject to additional revision by a parliamentary committee before a final vote at some point next year, securing approval "in principle" is likely to end any doubts about the legislation being passed. Opponents of the legislation will then start to focus on campaigning for appropriate safeguards to be put in place to protect the rights of people who refuse to promote same-sex marriage and ensure that no individual celebrant is forced to hold gay ceremonies against their will. Our survey reveals that 86 MSPs have confirmed they will vote for same-sex marriage, while 11 plan to vote against. However, the rebellion against the move could grow in the coming days, as ten MSPs say they remain undecided and a further 20 have refused to reveal how they will vote on the issue. Leader: First Minister Alex Salmond is one of the MSPs said to be voting in favour of gay marriage The decision to press ahead with the move comes despite the Scottish Government's biggest ever public consultation revealing that more than two-thirds of respondents opposed the plan. The issue has led to considerable tension within the SNP. Four Nationalist MSPs say they will definitely vote against the move - including Alasdair Allan, the Minister for Learning, Sciences and Scotland's Languages, as well as backbenchers Richard Lyle, John Mason and Dave Thompson. Mr Allan, who represents the Western Isles and is a former senior media relations officer at the Church of Scotland, said hundreds of his constituents have been in touch to urge him to back the "traditional definition of marriage." He said: "In responding to people, I have pointed out that I am supportive of the existing rights of same-sex couples to civil partnerships, and that I welcome the belated respect which society rightly gives gay people, but that I believe difficult issues are raised around the specific question of marriage. This view has also been informed by the strength of feeling which exists among many people in the islands. Among all these different views, the view which so many of my constituents have expressed to me has a right to be recorded, and for that reason it is my intention to vote against the Bill. The Scottish Mail on Sunday survey is the most detailed research ever carried out into the views of Scotland's MSPs on same-sex marriage. As all MSPs will be allowed to vote on the issue as a "matter of conscience" - without being told how to vote by party whips - the result is less predictable than on most issues in the Scottish parliament, where the SNP has a majority and is normally able to confidently press through its opposition. Split: The Scottish Conservatives were the only party to have more MSPs opposed to the legislation, which is embarrassing to Ruth Davidson, the party's openly gay leader who has been a prominent supporter The Scottish Conservatives were the only party to have more MSPs opposed to the legislation than supportive of it - with six saying they will vote against the Bill and just four saying they will vote for it. That is embarrassing for Ruth Davidson, the party's leader, who has been one of the most prominent supporters of the legislation at Holyrood. The Scottish Government is committed to a Scotland that is fair and equal and that is why we believe that same sex couples who wish should be allowed to marry as soon as possible Scottish Government Spokesman But Miss Davidson said: "I believe the forthcoming bill on same sex marriage is an issue of conscience, which is why I have given Conservative MSPs a free vote on the issue. I support same sex marriage and will be voting to pass this bill. The four SNP members who have said they will vote against the plans are expected to be joined by more rebels on Wednesday, with four nationalist MSPs saying they remain undecided and a further ten saying they won't reveal their view before voting later this week. Former SNP leader Gordon Wilson believes that pressing ahead with the legislation will cost the party votes in future elections - and urged MSPs to ensure they get proper protection for religious groups who don't want to hold same-sex marriages. He said: "Bland assurances will not necessarily deal with the realities of supervision of the legislation by the courts. "There's a majority for it but once you get the principle what then happens is it's about "on what terms"? Like any insurance policy, it's about the small print - look at what the small print says. That's my advice to MSPs - even if you're in favour, look at the small print and what might happen because the courts are outwith your control. Following Wednesday's vote, the Bill will then return to Holyrood's equal opportunities committee, which will consider any amendments which need to be made. It remains on track to be passed in time to allow the first gay weddings to take place in 2015. Opponents of same-sex marriage want more to be done to ensure that those who continue to believe in traditional marriage do not suffer discrimination in their career or have freedom of speech restricted. They fear that some professionals, such as teachers, could be sacked if they fail to promote gay marriage. Freedom: MSPs will be allowed to vote as a 'matter of conscience' when they cast their ballots at Holyrood A spokesman for the Scotland For Marriage pressure group, which includes representatives of the Catholic Church in Scotland and The Christian Institute, said: "The Scottish Government's promise of sufficient safeguards have been shown to be hollow. Real safeguards set out in amendments to the legislation are required to protect the rights and civil liberties of the majority of Scots who don't support this law. Among those set to vote against the Bill is Tory MSP Alex Johnstone, a member of the Scottish parliament's equal opportunities committee. He said: "There's been a substantial trend in recent years away from supporting traditional marriage as a basis for the raising of children and providing the cornerstone for society as a whole. At a time when we should have been looking for ways to underpin and reinforce marriage on that basis we seem to be obsessed with pursuing what I believe is an unjustified desire to provide same-sex marriage, so I think it is a step in the wrong direction as far as the support of marriage in society is concerned. However, Scottish Tory deputy leader Jackson Carlaw said he would support the Bill - while ensuring that any amendments can provide full protection to religions, faiths and congregations which don't want to take part. Colin Beattie, Nationalist MSP for Midlothian North and Musselburgh, said: "I don't think the case for making it different for gay people holds much water: everyone should be equal. I'm concerned about the people who are against but if you are a parliamentarian you have to deal with hard facts and logic on whether something should become law and it is hard to take into account religious views on that basis. A Scottish Government spokesman said: "The Scottish Government is committed to a Scotland that is fair and equal and that is why we believe that same sex couples who wish should be allowed to marry as soon as possible."