A majority of registered voters in Illinois say they support the legalization of marriage for gay and lesbian couples.

According to a statewide poll of 600 likely voters conducted by Fako & Associates and commissioned by Equality Illinois, the state's oldest and largest LGBT rights advocate, 52 percent of respondents favor a proposed law making Illinois the 15th state to adopt marriage equality, while 40 percent remain opposed. Eight percent refused to answer.

When pollsters shared information about the U.S. Supreme Court's June ruling which struck down a portion of the Defense of Marriage Act (DOMA), which led to the federal government recognizing the legal marriages of gay couples, support grew to 54 percent.

The poll comes a day before lawmakers reconvene for the fall session. Marriage equality proponents are lobbying for passage of a marriage bill which stalled in the House after clearing the Senate on Valentine's Day.

“With Illinois same-sex couples suffering because they cannot access federal benefits available to married couples, the time is now in the fall legislative session for the House to complete its unfinished business on the marriage bill,” Bernard Cherkasov, CEO of Equality Illinois, said in an emailed statement.

“With these poll results, there is certainly no political reason why representatives shouldn't pass it in overwhelming numbers. There are simply no excuses left. We expect every House member who has expressed support publicly or privately for marriage equality or who has been leaning in favor of it to vote 'aye.'”

A December, 2012 Public Policy Polling survey found proponents in Illinois leading on the issue by a 47-42 margin.

(Related: Majority support gay marriage in New Jersey, proponents lead in Illinois.)