The House State, Veterans and Military Affairs Committee voted along party lines during a 2-hour special legislative session called by Democratic Gov. John Hickenlooper, The New York Times reported.
"We saw this bill die even though a majority of members of the Senate and a majority of members of the House and the governor, as well as a vast majority of Coloradans, want to see this become law," state Rep. Mark Ferrandino, one of four openly gay state legislators. "It is very unfortunate. Families across Colorado are going to have to wait longer for equal rights in our state."
Supporters had argued for passage of the bill Monday after Republican House Speaker Frank McNulty assigned it to the committee, The Denver Post reported.
McNulty's move made it unlikely the measure would reach the House floor, where the Post said bipartisan support would have enabled it to pass.
The bill was assigned to the conservative committee the first day of a special session called by Gov. John Hickenlooper, a Democrat, after the House failed to debate the civil unions bill despite the fact there were enough votes to pass it.
In the fight over the bill, the Republican-controlled House killed 30 other bills the Post said would have passed otherwise.
Hickenlooper called the session to deal with civil unions and other issues, including funding for $55 million in water projects; penalties for driving under the influence of alcohol or drugs; stabilizing unemployment-insurance rates, creating "benefit corporations" in Colorado; and asking voters to amend the state constitution by repealing provisions considered obsolete, including a measure that barred local governments from prohibiting discrimination against gays.
McNulty criticized Hickenlooper for calling the special session.
"From our perspective, our side is focused on job creation and economic recovery," McNulty said. "We ought not and we should not be spending time on divisive social issues when unemployment remains far too high and far too many Coloradans are out of work. ... It's unfortunate that this scenario has played out where it appears that Governor Hickenlooper is out of touch with Coloradans."
Former Denver Mayor Wellington Webb, testifying for civil unions supporters, said the civil unions bill is "what we all know to be the right thing to do."
"Which side of history are you going to be on?" Webb asked.
Opponents of the bill also packed a hearing room, wearing white T-shirts reading, "Loving All, Protecting Marriage."