Colorado State Senator Pat Steadman on Monday introduced a bill that would give gay and lesbian couples many of the benefits and responsibilities of marriage.

Democratic Representative Mark Ferrandino is sponsoring the legislation in the House.

Steadman, an openly gay Democrat, said he's proposing the law because a 2006 voter-approved constitutional amendment bans gay marriage in the state.

“This is a method of recognizing committed relationships between two people and allowing them to access the full scope of protections in Colorado law,” Steadman told the Denver Post.

The paper noted that passage in the Democrat-controlled Senate was nearly guaranteed, but less likely is a win in the House, which is controlled by Republicans.

Ferrandino, who is also openly gay, said there is Republican support for the bill in the chamber.

If approved, Colorado would join New Jersey and Illinois in offering the union. Illinois Governor Pat Quinn signed his state's bill into law last month. Lawmakers in Hawaii are also poised to approved a similar measure.

A majority(52%) of Colorado residents favor legalizing gay marriage.