The multi-billion dollar five-year package, which passed by 231 votes to 191, offers a safety net for farmers and ranchers, regulates subsidies and aid and includes nutrition and conservation programs.

Democratic House speaker Nancy Pelosi hailed the bill as taking "America's farm policy in a new direction that stands with our farmers and ranchers and recognizes their vital role of providing food, fiber, and fuel for America and the world."

But Bush's Republican administration threatened to veto the legislation, partly over what it says are high subsidies, a major stumbling block in the Doha Round of global trade negotiations.

Some Republicans, who had been disposed to support the bill, withdrew their backing after Democrats added a tax hike on some foreign-owned companies with US subsidiaries to partly fund government nutrition programs.

Agriculture Secretary Mike Johanns blasted the "11th-hour" adoption late Thursday of the tax hike, saying it unfairly pits farmers against another sector in the economy.

"We have seen the polarizing impact of developing funding for farm policy under the cloak of secrecy," he said. "It's historic and, I might add, not in a positive way."

Farmers "advocated for new programs, they advocated for new policies, but they never advocated for new taxes," he said.

According to USDA research, he said, only one time was a tax hike included in a farm bill: in the Depression-era 1933 farm adjustment act.

"I can think of no quicker way to threaten the safety net than by asking someone else to pay extra for it," he said.

"Yesterday's action by the majority leadership narrowed support for the Farm Bill, and it lessened its chances for success, and it divided one great industry against another."

The head of the Republican minority in the House, John Boehner, complained that the new bill threatened the jobs of 5.1 million Americans.

"At a time when China, India and Russia are opening their doors to expand their economies and attract investment, these tax hikes send the signal to every potential investor in the global economy that it's not worth the hassle to invest in America," Boehner said.

The measure must now be reconciled with a Senate counterpart before it is presented to the president for signing.

The pressure is on to approve the 2007-2012 measure as the current bill expires on September 30, the end of the government's fiscal year.

The Bush administration says subsidy reductions in the new bill are not sufficient. It had sought an income cap of 200,000 dollars, averaged over three years. Republicans argue that the House bill would deprive about 7,000 farmers of subsidies, compared with the 38,000 that would be affected by their proposal.

The Bush administration is under fierce pressure to help unblock the WTO Doha Round, launched in the Qatari capital nearly six years ago and aimed at lowering trade barriers and encouraging development.

Developing nation critics of farm subsidies say they allow developed countries to dump excess production on world markets at an unfairly low cost, depriving many developing and poor countries of strengthening their own farm-sector exports.

The United States and the European Union, also known for lavish farm subsidies, have given a lukewarm response to the latest WTO proposals to cut farm subsidies.