Opponents are concerned that language in the bill is unclear on religious protections.
Steans has previously stressed that the bill does not change the definition of religious marriage.
"I think it's important to understand first [that] this is civil marriage we're talking about. We're not changing the definition of religious marriage. ... This really is civil marriage. Churches can choose to solemnize or not, or any faith can. But no one who does not want to has to," Steans said during a Jan. 17 appearance on Current TV.
The General Assembly's spring session begins February 5.
If Illinois approves gay marriage nearly twenty percent of the U.S. population will live in states recognizing marriage equality, according to the Human Rights Campaign.