Deputy First Minister Nicola Sturgeon risks losing her Holyrood seat if the SNP continues to press ahead with plans to redefine marriage, a former Party activist has said.
Adil Bhatti said most Roman Catholics and Muslims would not vote for her over the policy.
He warned Nicola Sturgeon that she would “lose more than she would gain” in her Glasgow Southside seat.
Mr Bhatti said: “The gay community don’t have that many votes compared to those that you would lose from the religious groups like the Muslims and the Catholics”.
He added: “There is an option the religious groups might not vote at all. I don’t think the Muslim and Catholic population will vote for her.
“I can’t say that there will be a complete blackout but the majority will vote against her.”
Until recently it was Nicola Sturgeon who was spearheading the plans to redefine marriage in Scotland.
Mr Bhatti, a former member of the SNP’s national council, said: “When people think about same-sex marriage they think of the SNP mainly, not any other party.”
The Scottish Government is currently running a consultation on the details of its same-sex marriage Bill.
Scotland for Marriage, which is campaigning against the change, says First Minister Alex Salmond has broken his promise to protect civil liberties in the Bill.
Mr Salmond made assurances to traditional marriage supporters that the draft Bill would provide protections for freedom of speech and conscience.
But Scotland for Marriage said that although there has been “some movement” on freedom of speech, key concerns have been ignored.