Openly gay state Rep. Greg Harris (D-Chicago) has filed legislation that would allow same-sex couples to marry in Illinois.

The bill is slated for discussion Tuesday in the Youth and Family Committee and a large number of gay and lesbian couples are expected to pack the committee room. But even Harris admits it will be tough to get the measure to a vote in the House.

Two years ago, a civil union bill introduced by Harris died when the session ended and conservative groups already have made it known they will fight the marriage bill. They've work to push for a state constitutional amendment to ban same-sex marriage they hope will make it to the ballot in 2010.