Legal gay marriage may be coming to Illinois as soon as next month.

After counting heads and consulting with legislative leaders, the chief sponsors of a bill to permit same-sex couples to get married in the state disclosed this morning that they intend to push for a vote in the General Assembly's lame-duck session, which will occur over two weeks just after New Year's.

And, in an indication of how big a campaign the pro side is launching, they've hired the firm founded by top presidential adviser David Axelrod to help them with media, organization and outreach to potential supporters, including corporate officials.

As recently as a couple of weeks ago, sponsors had indicated that a January vote was highly unlikely, with several other big measures likely to take precedence, including reform of state pension plans and a gambling bill that would authorize a Chicago casino.

But that has changed.

"We think we can get this done in January," said state Sen. Heather Steans, D-Chicago, who will be the chief Senate sponsor of the bill. With Gov. Pat Quinn saying he'd like to see a bill sooner rather than later, and other legislative chiefs apparently signing off, too, "the timing is right," Ms. Steans said.

A similar message came from the chief House sponsor, Rep. Greg Harris, also a North Side Democrat.

"The timing is right for us to push this," said Mr. Harris, who spoke with Ms. Steans in a joint conference call today. Some lawmakers who had been opposed now are taking a second look, Mr. Harris said, in view of the Election Day decision by voters in Maine, Maryland and Washington state. "Folks are seeing what's going on around the country."

The exact language of the final bill has not yet been disclosed. But both lawmakers said their measure will include an exemption for religious groups that would allow them to conduct or not conduct weddings involving gay men and lesbians, as they prefer.

Illinois a couple of years ago authorized civil unions that grant many of the privileges and rights of marriage. But the political mood of the country since has evolved, and Ms. Steans said all Illinoisans now need more than "second-class status" when it comes to marriage.

Pushing for a vote in January could allow bill sponsors to capture votes from several retiring lawmakers who at other times might be less inclined to provide a vote.

Insiders say that the Senate clearly leans in favor of passage but that the tally is closer in the House. Democrats control both chambers, and only a simple majority is needed for passage in both.

Being paid to assist in the campaign will be ASGK Public Strategies, one of the city's better-known media strategy firms. Mr. Axelrod sold his interest in the firm years ago, but the company has expanded its profile, recently being hired by the Regional Transportation Authority to coordinate its Washington lobbying.

No one at this point is disclosing who's paying for the campaign, but Chicago is home to several nationally known gay and lesbian political fundraisers.

Nine states and the District of Columbia now have legalized same-sex marriage, either by legislative or court action. Federal law bans extending benefits such as joint income tax returns to gay couples, but the U.S. Supreme Court recently agreed to hear a challenge to that practice.

1 p.m. update:

That didn't take long.

Though some religious groups surely will oppose the bill, exemption or not, I'm told that Mayor Rahm Emanuel already has started calling lawmakers to urge a yes vote. The mayor awhile back had indicated that passing a same-sex marriage bill was one of his top legislative priorities.