Chambliss, the top-ranking Republican on the Senate Agriculture Committee, was the chief mediator between the White House and the Democratic-controlled Congress on the legislation.

Bush opposes the measure's $300 billion price tag. The President and other critics have called 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 "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.

The House and Senate could vote on the bill next week. Its unclear whether supporters will have enough votes to override a veto.