Colorado lawmakers will soon vote on a measure to allow gay couples civil unions. The measure is expected to pass its first vote.

On Wednesday, a Senate committee will hear testimony from those supporting and opposed to civil unions, and the bill is expected to be sent to the governor’s desk later this legislative session, the Coloradoan reports.

Democrats had tried to pass civil union legislation in the past two years, but House Republicans had defeated the measure.

Democratic Governor John Hickenlooper, supports equal marriage, and Democrats control both chambers of the legislature, so the bill is expected to pass this time around.

Nine US states have already decided to legalise full same-sex marriage, beginning with Maine and Maryland in November of 2012. Illinois has plans to vote on the topic later this year. Civil partnerships are available in several other US states.

In 2011, the governor of the US state of Delaware signed a civil unions bill into law.

Yesterday, the US state of Rhode Island was one step closer to legalising equal marriage, after its House Judiciary Committee unanimously approved a bill which would make it legal.

Last week three hundred people, both for and against equal marriage, signed up to speak at hearings at Rhode Island’s State House and hundreds more gathered outside to protest against proceedings.