Palatine-based Rep. Tom Morrision filed the House Joint Resolution 95, also named "Defense of Marriage" July 19. Reps. David Reis, Paul Evans and Dwight Kay are sponsoring the measure.

The resolution states, 'That we oppose any efforts to extend the institution of marriage to 2 individuals of the same sex, whether by statute or by court decision…"

The measure comes in the wake of two lawsuits filed by the American Civil Liberties Union and Lambda Legal that aim to win marriage equality in the state. A group of pro-gay state Reps. backed a bill to legalize same-sex marriage earlier this year, but the bill languished in committee.

The July resolution specifically names the Cook County marriage lawsuits, which elected officials have refused to defend. Two downstate clerks are intervening in the case in support of the ban.

The resolution further urges support for a 2014 constitutional amendment against same-sex marriage.

LGBT policy organization The Civil Rights Agenda (TCRA) denounced the measure in a statement.

"Obviously with the General Assembly in recess for the year this will not be going anywhere fast," said Lowell Jaffe, political and policy director for TCRA. "But, with that said, we take these attacks on the LGBT community very seriously and will continue to fight them."

TCRA Marriage Project Director Rick Garcia noted that past constitutional amendments against same-sex marriage in the state have failed.