MSPs will vote for the first time today on a bill to legalise same sex marriage in Scotland.
Health Secretary Alex Neil is urging politicians from all parties to back the change, arguing that "marriage is about love, not gender".
But some religious groups remain opposed to the move.
The Marriage and Civil Partnership Bill aims to protect the rights of religious celebrants and groups opposed to allowing gay couples to wed.
Under the plans, protection will be offered to individual celebrants who feel it would go against their personal faith to carry out gay weddings.
"At the heart of this issue there is one simple fact: a marriage is about love, not gender.
"I believe it's essential that all couples in Scotland know they have the same rights and privileges, and the same ability to get married.
"I hope that our national parliament takes this opportunity to send a clear signal that in a modern Scotland we are passionate promoters and defenders of equality, and I would urge MSPs to support the Bill."