A poll has found that supporters of same-sex marriage in Colorado outnumber opponents by nearly two to one, despite the state maintaining a constitutional ban.

According to a poll conducted by researchers at Quinnipiac University, an overwhelming majority of voters in Colorado support same-sex marriage.

The poll, which surveyed 1298 registered voters, found that 61%supported equal marriage, with just 33% opposed to it.

Support surged to 81% in the 18 to 29 age group, and the only age group to oppose it was over 65s, where 48% opposed and 44% supported.

The statistics show a huge turnaround from when the state added a constitutional ban on same-sex marriage in 2006 with the support of 53 percent of voters.

It mirrors a trend nationally in the US, after a poll last month found that 59% supported the right of gay couples to get married, while 34% opposed.

Last March Colorado passed a law allowing same-sex civil unions in the state, which came into effect two months later.

Earlier this month, a group of faith leaders in the state formed a coalition to lobby in favour of same-sex marriage.

A statement from the group said: “As people of faith, we believe in practicing the Golden Rule, treating others as we would want to be treated.

“All loving and committed couples deserve to be treated with respect, and the freedom to marry gives them that respect.”

The state’s constitution says: “Only a marriage between one man and one woman shall be valid or recognized as a marriage in this state.”