Supporters of gay marriage in Illinois say they have the votes to pass a proposed law in the next 10 days.

As the Illinois General Assembly's regular session nears its end, advocates insist the measure will clear its final legislative hurdle.

The bill, approved by the Senate on Valentine's Day and a House panel in March, has the support of Democratic Governor Pat Quinn, leaving only a vote in the House standing in its way to becoming law.

“I have absolutely no doubt we're going to be done with this by May 31,” Jim Bennett, Midwest regional director for Lambda Legal, told gay weekly Windy City Media Group. “I believe that this bill is going to pass.”

Rick Garcia, policy adviser for The Civil Rights Agenda, agreed.

“I believe we're there,” he said. “The cake is baked. We're waiting for the icing.”

Passage in the House requires 60 votes. Democrats have 71 members in the chamber and two Republicans have pledged their support for the bill.

If the marriage law is approved, Illinois would become the 13th state to legalize such unions and the fourth this year.