Illinois Governor Pat Quinn will sign a bill that recognizes gay and lesbian couples with civil unions next Monday, reported.

“Plan to attend and witness history taking place,” wrote openly gay State Rep. Greg Harris on his Facebook page.

Over a thousand people are expected to attend the signing ceremony to take place at 4PM at the Chicago Cultural Center in Chicago's Loop.

Lawmakers approved the legislation during last month's lame-duck session of the Legislature.

The law will go into effect on July 1, 2011.

A day after the Legislature approved the bill, Chicago Mayor Richard Daley hailed the legislation and urged the state to press on to full marriage.

“Finally, they [state lawmakers] realized they should have the same rights under state law,” Daley told the Chicago Sun-Times. “But eventually, [gay] marriage will take place. It has to … We have to move faster.”

Daley is among the lawmakers expected to attend Monday's ceremony.

The bill was opposed by socially conservative groups, including the Catholic Conference of Illinois and the National Organization for Marriage (NOM).

Illinois becomes the second state after New Jersey to offer civil unions. Vermont, the first state to legalize such unions, now offers gay couples marriage. Hawaii lawmakers will take up a similar measure later this year.