The Finnish Parliament is set for a vote on Friday on a proposal which would make marriage gender-neutral, and extend marriage rights to gay and lesbian couples.
The proposed legislation would change the definition of marriage in the Marriage Act, to a gender-neutral form, as opposed to that between one man and one woman.
Those on both sides of the debate have voiced strong opinions.
Politically it is unclear which way the vote will go, however it is expected to be close.
One report suggested the legislation will pass as 99 MPs have expressed support with 86 against, however there were 14 MPs whose positions remained unknown.