Imams from across Scotland's largest Islamic community in Glasgow, said Muslims should ask individual candidates rather than political parties their position on the issue and religious ceremonies for civil partnerships, before deciding on their voting intention.
The city is home to tens of thousands of Muslim voters.
Combined with many Christians also voicing opposition to gay marriage, one leading figure within the Islamic community believes they will be a crucial factor in a tight race to take control of the city.
The faith's leaders have already endorsed the Scotland For Marriage campaign which supports the current definition of marriage and opposes any re-classification.
Although issued by the Council of Glasgow Imams, the message is being sent to Muslims all over Scotland.
However, one of Holyrood's two Scots-Asian MSPs has dismissed the notion anti-same- sex marriage voters could be crucial,claiming the Muslim community was a more sophisticated electorate and would be looking beyond single-issue politics.
Another leading member told The Herald that Muslims would be more inclined to vote for their economic betterment than anything theological.
The launch at Glasgow's Central Mosque was spearheaded by Bashir Maan. The former Labour councillor and Police Board chairman was removed from his honorary post as chairman of an equalities charity for a public attack on homosexuality and claims gay sex education in schools led to children "being robbed of childhood". He said the stance was similar to that taken by the Catholic Church and other Christian groups.
It comes days after the Catholic Knights of St Columba were accompanied by Muslims in delivering a petition against same-sex marriage to the office of Deputy First Minister Nicola Sturgeon.
Mr Maan said: "Every voter will have to make sure the person they are voting for is not in favour of same-sex marriage. It is up to them who to vote for but they should ask every person who comes to them and asks for their support.
"Catholics within the SNP and Labour also feel the same. We've worked with Catholics in the past. There's no dividing line here. With many Catholics doing the same, how people vote could be critical in the election's outcome."
However, Hanzala Malik, Glasgow Labour MSP, said: "No religious faith will be forced to hold a gay marriage within their place of worship. Assurances have been given on that. And while Bashir Maan is voicing an opinion, and that's the cornerstone of democracy, people of any community are living in the real world and want more than a single view on faith to be the focus of an elected representative.
"The Muslim community expects others to give us freedom so why would we deny it to others? And to say this could affect the outcome of the election is just pie in the sky."
One leading Scottish Muslim said: "The community won't be swayed by what the mosque says. They already have their allegiances. They'll be supporting Labour or the SNP because of the pounds in their pockets rather than anything theological."
An SNP spokeswoman said: "It will be MSPs, not councillors, who vote on any legislation that may be brought forward as a result of the consultation. The Scottish Government is clear that, whatever the way forward, faith groups and their celebrants would not be obliged to solemnise same-sex marriages."