An amendment to the rules of the United States' largest Presbyterian denomination to recognise gay marriage has gained considerable support in its regional bodies, with 51 of 172 presbyteries already voting in favour of redefining marriage to include same-sex couples. The denomination's remaining presbyteries have until June to cast their votes to make the final decision. Currently, the Book of Order defines marriage as being between ‘a man and a woman.’ The new language would remove the gender specific terminology, replacing it with ‘two people.’ If a majority ratifies the amendment, it would take effect on 21 June 2015.