The Colorado Senate on Thursday approved a bill that would recognize gay and lesbian couples with civil unions, the AP reported.

The final 23 to 12 tally wasn't a surprise. Senators twice approved Senator Pat Steadman's bill with a voice vote on Wednesday.

Surprising were the actions of three Republicans who crossed the aisle to support the measure, which wasn't even in need of their assistance.

Republican Senators Jean White, Nancy Spence and Ellen Roberts backed the bill.

During Wednesday's debate, Steadman, who is openly gay, told colleagues that the bill was essential for ensuring “very basic, but very important legal protections … that no family should be without.”

The measure now moves to the House, where Democratic Representative Mark Ferrandino will carry the bill.

Ferrandino has claimed there is Republican support for the measure in the GOP-controlled House. But whether the measure reaches the House floor remains to be seen. Supporters worry that House Speaker Frank McNulty, a Highlands Ranch Republican, will assign the bill to a hostile committee, thereby killing it.

The Colorado Statesman has quoted McNulty as saying: “When we get it, we will assign it to committee and wherever it's assigned, it will receive a fair hearing.”

Opponents of the measure have attempted to paint civil unions as analogous to marriage, most likely in an attempt to lay the groundwork for a legal challenge to the measure if approved by lawmakers. In 2006, voters adopted a constitutional amendment that defines marriage as a heterosexual union.

Three states – Illinois, Hawaii and New Jersey – currently offer civil unions. A similar bill was introduced in Delaware on Tuesday.