ATLANTA - Georgia lawmakers plunged into the frantic, final day of their legislative session on Thursday, with no word on whether they would strike a deal on a contentious immigration proposal before the midnight deadline.

The General Assembly has already tackled major legislation on issues including the HOPE scholarship, Sunday alcohol sales and the 2012 budget. A proposal to overhaul the state's tax code fell apart in the 11th hour.

Illegal immigration remains the biggest issue in limbo. The House passed a tougher bill, while the Senate approved a version with changes sought by business and agricultural groups worried they could be penalized for not screening the immigration status of employees. The Senate can either agree to changes made in the House or send the bill to a conference committee to hammer out a compromise.

The immigration battle was already coloring the day even before the issue came up. A testy House Speaker David Ralston ordered that a flier distributed by Democratic state Rep. Pedro Marin be removed from members' desks because it contained a column suggesting that the immigration bill's sponsor, Republican state Rep. Matt Ramsey, had lied.

Ralston said the handout violated rules against personal attacks on representatives.

"I take a very dim view of that," Ralston said.

The House was off to a faster start Thursday, giving final passage to a bill that extends a hefty tax break for Savannah, Ga.-based Gulfstream Aerospace. That break on the sale of aircraft parts on planes repaired or maintained in Georgia will cost the state $4.2 million in revenue next year.

The state Senate tacked on an amendment providing a tax break for tourist attractions.

Rep. Ron Stephens, a Savannah Republican, said it encourages tourist attractions in the state "similar to Disney World." But Republican state Rep. Mark Hatfield, of Waycross, said it allows tourist attraction owners to profit from pocket sales tax collections.

The bill squeaked by after Ralston took the unusual step of casting the deciding vote.

A tax break for another hometown corporate giant, Delta Air Lines, was headed back to the state Senate after the House refused to sign off on changes made in that chamber.

"The Senate has, as usual, messed it up," sponsor state Rep. Jay Roberts, R-Ocilla, said.

The House gave final passage to a bill that removes distance restrictions on South Georgia hunters who use bait to attract deer and feral hog hunters Opponents labeled such hunting unsportsmanlike and unethical. But supporters say it will help thin out booming deer and hog populations.

Also heading to Gov. Nathan Deal for his signature is a bill to require antifreeze be made bitter tasting to deter animals from ingesting the sweet-smelling substance. It mandates that the bitter-tasting chemical denatonium benzoate be added to antifreeze sold in Georgia.

Lawmakers have signed off on a bill that creates an advisory panel to look at an overhaul of the state's tough sentencing laws. The joint committee will make recommendations in time for lawmakers to act next year.

Other key measures still to be decided include one that would close a lobbying loophole allowing gifts to staff of public employees and another that would give the governor authority to appoint members to the embattled Atlanta Public School board.

Also up in the air is a bill that would allow the sale of insurance across state lines. Supporters say it would help drive insurance costs down in the state by introducing competition. But opponents - many of them female legislators - said it would weaken insurance protections in the state by allowing policies that don't have to meet tough Georgia coverage mandates.

Lawmakers are expected to return to the state Capitol in late summer for a special session to deal with redrawing congressional and legislative district lines to conform to new U.S. Census data.