The Indiana House of Representatives are evenly split on a constitutional amendment currently being discussed that would ban same-sex marriage in the state.

An Indianapolis Star poll found that of the 100 representatives, 38 currently support the ban, while 38 are opposed, 13 are undecided, and 11 declined to comment.

That is a huge departure from the outcome of the initial vote on the same amendment in 2011, which was approved by 70 votes to 26.

The numbers indicate that over a third of representatives who supported the ban in 2011 are now opposed to it or are wavering.

According to Megan Robertson, campaign manager for Freedom Indiana, who oppose the amendment, the close vote on the amendment “shows how divisive it is, which is why it shouldn’t be put into our constitution.”

Democrats in the state are focussing on removing a clause which bans civil unions, and which could strip employment benefits from gay couples.

Even if it passes in the House, the amendment faces tough challenges before it becomes law, as it also has to pass the Senate and be adopted in a referendum.

The President of the Senate David Long said on Friday that the amendment would also go to the Senate Judiciary Committee, should it pass in the House.

The move bucks the trend of other states in recent months, where many existing same-sex marriage bans are facing attempts to have them repealed, or are facing substantial legal challenges.

Indiana already has a law in place from 1986 which bans same-sex marriage, but Republicans are trying to strengthen their position given legal challenges in other states, and are pinning their hopes on the extra weight winning a referendum would add.