Rep. Tim Kelly, R-Red Wing, proposed a bill Wednesday afternoon that would allow civil unions for same-sex couples, MPR reports.

Kelly calls the measure a "fallback plan" if the gay marriage bill in Minnesota fails. However, DFL House leaders say civil unions are not an alternative to marriage.

"It's a little late to be coming with something like this to deflect the momentum that's out there to really make sure that it's marriage equality, not a second class status that doesn't work," DFL Rep. Karen Clark, sponsor of the House version of the gay marriage bill, told MPR. "It just plain doesn't work."

Civil unions are considered a compromise among many who want gay and lesbian couples to have some recognition, but not be allowed to marry, the Star Tribune notes.

House and Senate panels approved legislation that would legalize gay marriage, and full chamber votes are expected later in the legislative session.

The chief sponsor of the gay marriage bill, Sen. Scott Dibble, DFL-Minneapolis, also said civil unions are insufficient, calling them "separate but equal," the Pioneer Press reported. He said civil unions create new legal problems for gay couples.

Richard Carlbom, who is leading a lobby effort in the campaign for gay marriage, has said civil unions don't go far enough to protect couples.

Kelly was one of four Republicans who broke with their party in 2011 in opposing an amendment to the Minnesota state constitution that would have banned gay marriage. (Voters rejected that amendment.)