The Senate in the US state of Nevada passed a bill on Monday to begin the repeal of a voter-approved constitutional amendement banning equal marriage.

Following an hour of heated debate around Senate Joint Resolution 13, including state Senator Kelvin Atkinson coming out, the Senate voted 12-9 in favour of the bill which begins the long road to legalising equal marriage in the state.

One Senator, Ben Kieckhefer, was the only Republican to join his 11 Democratic peers to vote in favour of the measure.

If the measure is passed by the Assembly, which has a 27-15 Democratic advantage, and both the Senate and Assembly pass it again in 2015, the repeal would be put to voters in 2016.

Last week the bill was subject to an amendment to add protections for religious groups, which says none would be forced to perform same-sex marriages.

A week prior, the resolution, which was passed by the committee 3 votes to 2, set out that the state of Nevada would recognise marriage regardless of gender.

In 2002, voters in Nevada approved an amendment to the state constitution stating that “only a marriage between a male and female person shall be recognized and given effect in this state.” At that point, the vote was 337,197 to 164,573 for the amendment.

In June 2009, The law allowing domestic partnerships was passed, and became effective in September of that year, which allowed same-sex couples some rights, but not the full benefits of marriage.