A bill to allow same-sex couples to form civil unions in Colorado is expected to move forward following months of stalling in the Colorado legislature.

The bill to give gay couples almost identical rights to straight married couples is expected to pass in the Democratic controlled Senate because a similar bill passed comfortably there last year by 23 to 12 votes.

However, it is far from clear if the measure will pass in the Republican dominated House of Representatives. The bill last year failed by just one vote.

This time, the bill is supported by some Republican politicians although activists warn that it is possible that it will fail again. Other worry that the measure will not complete its progress through the legislature before the end of the current session.

In 2006, Colorado voters rejected a proposition to allow gay couples to marry.

Last year, Republican Jean White said she was voting for the measure on behalf of her gay niece and nephew. She said: “It occurred to me that if I did not come to the mic in support of this bill today, that I would be voting quietly for it but not having the courage to stand up for what is right, not having the courage for me to step out of the shadows and tell my story.”