The organisers of a campaign to put equal marriage on a ballot in the US state of Arizona in 2014, have dropped the effort in favour of waiting until the next chance.

Advocacy group, the Equal Marriage Campaign has said it did have broad support for the measure, but that key national advocacy groups withheld backing needed to make it on for 2014.

The national groups were in favour of waiting until 2016 to put equal marriage on the ballot in Arizona, and Equal Marriage Arizona has conceded that will be the case.

A ballot measure in 2014 did not leave enough time to rally support, the groups had said. The larger voter turnout in 2016, a presidential election year, would help the support for a constitutional amendment, they said.

Equal Marriage Arizona has said its supporters can return completed petitions to the campaign for destruction.

13 states in the US, and the District of Columbia, legally recognise equal marriage. The New Mexico Supreme Court has agreed to take on the case of several counties which have begun issuing marriage licences to same-sex couples. 

Moves to overturn the equal marriage ban in the US state of Ohio are building momentum, with a three-city announcement of the Why Marriage Matters campaign.

The Governor of the US state of Hawaii yesterday called for a special legislative session to move forward a bill that could legalise same-sex marriage.