WASHINGTON (Map, News) - Sen. Saxby Chambliss of Georgia said he's ready to join Democratic leaders to fight President Bush's threatened veto of the farm bill unveiled Thursday.

Chambliss, the top-ranking Republican on the Senate Agriculture Committee, has been the chief mediator between the White House and the Democratic-controlled Congress on the sprawling legislation, particularly on Bush's objections to its $300 billion price tag. Last week, Chambliss sat down for a private lunch with Bush at the White House, trying to persuade the president that Congress was making significant concessions.

But just hours after House and Senate leaders announced Thursday they had agreed on a final bill, the White House said that Bush would veto the measure.

"This is a very balanced farm bill," Chambliss said in an interview. "We have addressed each and every one of (his) concerns. We have not given him everything he wanted, but we have moved very much in his direction."

Bush has joined with critics from the right and left in calling for sharp cuts to crop subsidies, pointing to millionaire farmers and landholders who reap benefits under the current system.

But Chambliss and other farm-state lawmakers are fighting to protect the funding, saying it provides a critical "safety net" when the market drops. Southern growers say they need the government help because regional crops such as cotton, rice and peanuts are more expensive to grow than others and require larger operations to compete.

Under the legislation announced Thursday, farmers making up to $750,000 in farm income annually would be eligible for government payments - or $1.5 million for a married couple if both individuals are farmers. Landowners who earn up to $500,000 in non-farm income also would be eligible.

Bush has sought to eliminate payments to those making more than $200,000, but he has indicated he could accept a limit of $500,000. Current law allows payments for those making up to $2.5 million.

"Those are major changes to the payment limitation," Chambliss said, maintaining that the subsidy for landowners helps tenant farmers get cheaper rent. "There's going to be a lot of farmers who are affected by this."

The House and Senate could vote on the bill next week. It was unclear whether supporters would have enough votes to override a veto, but they will be looking to Chambliss to build support, particularly among conservatives.

"He has really been the glue that has held this bill together," said Democratic Sen. Kent Conrad of North Dakota.