The Coalition to Protect Children & Marriage was announced Dec. 18.

Among its listed members is Peter Breen, executive director of the Thomas More Society, and the lead attorney battling two lawsuits that seek to overturn the state's ban on same-sex marriage.

Other groups included the Illinois Family Institute, Eagle Forum of Illinois, Abstinence and Marriage Partnership, Illinois Citizens for Life PAC, Lake County Right to Life, Concerned Christian Americans and Family-Pac, according to a press release. That release notes that other groups will likely be added to the coaltion.

Paul Caprio, director of Family-Pac, said that the coalition would use the resources of those organizations to lobby against same-sex marriage in Illinois.

He said that the question of same-sex marriage in Illinois is now a federal issue, since civil unions grant same-sex couples the same rights as married heterosexual couples.

"Traditional marriage, between one man and one woman, our existing state law, developed and survived for thousands of years because it is the best familial arrangement for the protection of children and, therefore, for the future continuation of society," Caprio said in a statement.

LGBT advocates blasted the coalition as extreme.

"I think it's a far-right attempt to protect their form of bigotry," said Joe Murray, executive director of the LGBT Catholic organization the Rainbow Sash Movement.

"These are just the same-old tired anti-gay groups and individuals that have fought against gay protections for years," said Rick Garcia, senior policy advisor for The Civil Rights Agenda, in a statement. "They have lost in the past and they will lose again."

Some of the groups included are faith-based.

Not included in the list of participating groups, however, is the Catholic Conference of Illinois, which has historically opposed LGBT rights. A spokesperson for the Conference confirmed that the Conference was not involved with the coalition.