A group of dissident lawmakers led by Representatives Ron Kind, Democrat of Wisconsin, and Jeff Flake, Republican of Arizona, is still pushing a plan to curtail the subsidies sharply.

But they have been largely outmuscled by the Agriculture Committee. It 46 members are slightly more than 10 percent of the House but their districts received more than 40 percent of all farm subsidies from 2003 to 2005, according to a database compiled by the Environmental Working Group, which opposes the subsidies.

Critics in Congress include fiscal conservatives who deride the payments as wasteful government spending and liberals who call them corporate welfare for agribusiness. All say the measure will simply perpetuate the overly generous subsidy system, at a point when American farmers are well-positioned to weather changes.

“When farm prosperity is as good as it is right now, this is the time to reform,” said Representative Paul D. Ryan, Republican of Wisconsin and a member of the dissident group. “If we can’t reform these farm programs at this moment in our history, we will never be able to do it.”

The group has proposed an amendment to the farm bill that would cut subsidies and increase spending on environmental conservation, rural development and nutrition programs, including food banks. It would end subsidies to farmers earning more than $250,000 a year, similar to the $200,000 cap proposed by the Bush administration. It would also substantially limit payments that farmers receive under guaranteed loan programs.

The effort by Mr. Kind has exposed divisions among House Democrats, some of whom argue that he could cost the party its new majority. The fear is that freshmen Democrats from rural swing districts could lose their seats if voters blamed them for lower farm subsidies. Mr. Kind rejected such assertions. “The vast majority of our new members benefit from our proposal,” he said.

The White House, in a statement Wednesday, said that Mr. Bush would veto the farm bill in its current form because it was too expensive and would require raising taxes while fixing the subsidies.