The White House has threatened to veto a Republican-drafted farm bill, scheduled for a vote in the House on Thursday, that expands the taxpayer-subsidized crop insurance program but omits food stamps for the poor.

The farm subsidy bill was unveiled late Wednesday by House Republican leaders, who were embarrassed by the defeat last month of a $500 billion, five-year farm bill that included the largest cuts in food stamps in a generation.

Fiscally conservative Republicans wanted more cuts in farm program and food stamp spending. Leaders said no amendments would be allowed to the new bill, which they hoped to pass before adjourning for the week on Thursday.

Traditionally, farm bills are enacted by a partnership of rural lawmakers interested in agricultural programs and urban supporters of food stamps and other public nutrition programs.

But Republican leaders split the bill in two with the aim of attracting enough votes from their party to pass the farm subsidy portion. A separate food stamps bill would, in theory, come later.

In a statement late on Wednesday, the White House said it would veto the 608-page farm subsidy bill because it "does not contain sufficient commodity and crop insurance reforms" and it omitted food stamps, formally named the Supplemental Nutrition Assistance Program.

"This bill ... fails to reauthorize nutrition programs, which benefit millions of Americans - in rural, suburban and urban areas alike," said the White House. "The Supplemental Nutrition Assistance Program is a cornerstone of our nation's food assistance safety net, and should not be left behind as the rest of the Farm Bill advances."

The farm subsidy bill would cut spending by $14 billion over 10 years, chiefly by ending the $5 billion a year "direct payment" subsidy. It would expand the taxpayer-subsidized crop insurance program by 10 percent, or $9 billion, over 10 years, including a provision that would shield crop revenue from drops of more than 11 percent of average.

"Republicans are determined to de-fund nutrition assistance. Shame on you," said Congressman G.K. Butterfield, North Carolina Democrat, when the House opened debate for the day.