President Obama is endorsing a proposal by the Illinois legislature to legalize gay marriage, a White House spokesman told Reuters on Sunday.
It's an unusual move by a president - most of whom rarely weigh in on state legislative matters. Obama served in the Illinois state senate.
Obama, who said earlier this year that he supports same-sex marriage, believes "it's wrong to prevent couples who are in loving, committed relationships and want to marry, from doing so," said White House spokesman Shin Inouye.
"Were the president still in the Illinois State Legislature, he would support this measure that would treat all Illinois couples equally," Inouye said.
Chicago state Senator Heather Steans will introduce a gay marriage proposal this week, said Rikeesha Phelon, spokeswoman for Illinois Senate President John Cullerton. She added that Democratic leaders are confident they have the votes to win approval - possibly even before the legislature's newly elected Democratic super-majority takes office on January 10.
If it passes, that would make Illinois the tenth state to approve same-sex nuptials.
Passage in President Barack Obama's home state would be a symbolic victory for gay rights activists, particularly after the president endorsed same-sex marriage in May.
One issue to be resolved is whether Illinois should allow religious groups the option of declining to perform same-sex marriages. New York granted such an exception in 2011 in order to secure the legislative votes to legalize gay marriage there.
No Midwest state has approved gay marriage by a vote of its legislature. Iowa's Supreme Court ruled in 2009 that same-sex marriage was legal, a decision some opponents have been trying to overturn ever since.
In June, 2011, Illinois legalized civil unions, which grant some of the rights of marriage to same sex partners. But gay rights activists said that did not go far enough.
All prominent Democrats in Illinois have endorsed gay marriage, including Chicago Mayor Rahm Emanuel and Governor Pat Quinn, as well as 260 Illinois faith leaders who published a letter supporting same-sex marriage last week.
The Catholic Conference of Illinois, which represents Catholic bishops in the state, said on its website that marriage should be reserved for a man and a woman.
Nine of the 50 U.S. states plus the District of Columbia, have already legalized gay marriage. Another 31 states have passed constitutional amendments banning it.
(Writing by Karen Brooks; editing by Todd Eastham)