The legislation would cut $2 billion a year from food stamps while raising subsidies for several crops. Though it has support from rural lawmakers across the political spectrum, it is unclear whether Republican leaders will be able to gather the votes they need to pass the bill.

Many Republicans are seeking deeper cuts in the $80 billion-a-year food stamp program and say they’ll vote against the measure. They’re backed by conservative groups which are lobbying aggressively against it.

Democratic support is equally shaky. Liberals are rallying against the measure because they say the food stamp cuts will take as many as 2 million recipients off the rolls. The White House has threatened a veto, saying more money should be cut from farm subsidies and less from food stamps.

The bill calls for spending of almost $100 billion a year on food and farm programs.

In an effort to push the legislation through, House Speaker John Boehner, R-Ohio, said last week that he will vote for it, while making it clear that he doesn’t really like it. He said he wants to get the bill to a House-Senate conference and that passing the bill is better than doing nothing. The legislation would cut around $4 billion a year in overall spending on farm and nutrition programs.

Democratic leaders have said they will wait to see how the chamber votes on amendments but so far have signaled opposition to the measure. Democratic leader Nancy Pelosi of California is a “likely no” on the bill, according to an aide, and No. 2 House Democrat Steny Hoyer of Maryland called the food stamp cuts “irresponsible” on Tuesday.

House Agriculture Chairman Frank Lucas, R-Okla., pleaded for votes on the House floor, saying a robust farm policy is necessary to avoid farm crises like those in the 1930s and 1980s.

“I will work with all of you to improve this draft,” he said. “I ask you to work with me.”

Lucas called his bill the “most reform-minded bill in decades,” saying it would make needed cuts to food stamps and eliminate $5 billion a year in direct payments, subsidies that are paid to farmers whether they grow or not. The bill also expands crop insurance and makes it easier for rice and peanut farmers to collect subsidies.

Republicans late Tuesday released a list of 103 amendments that will be considered, with debate on the amendments expected to begin on Wednesday.

It was uncertain how those amendment votes could affect the vote on final passage, which could occur this week or next. Any alterations to the delicate balance of farm subsidy support included in the bill could cause members who represent the regions or crops affected to turn against it. Amendments targeting rice, peanut, sugar and dairy subsidies, among other crops, are expected to have contentious votes. The chamber will also vote on a Democratic amendment to eliminate the food stamp cuts.

It has been more than five years since the House passed a farm bill. Since then, Republicans took control of the chamber and more than 200 new members have been elected — many of them conservatives who replaced rural Democrats.

The politics of farm and food aid have also changed since then. Farm country is enjoying record-high prices and is one of the most profitable sectors of the economy, causing many lawmakers to question why farmers still receive more than $15 billion a year in subsidies. And the food stamp program has doubled in cost as the economy has struggled.

Farm groups were scrambling Tuesday to lobby lawmakers on the bill.

Chandler Goule, a lobbyist for the National Farmers Union, said his group was telling Democrats that the food stamp cuts likely would be reduced in a House-Senate conference because the Senate farm bill passed last week has a much smaller cut — about a fifth of the amount of the House cuts, or $400 million a year. With the presidential veto looming, lawmakers will have to bring that number down, Goule said.

“We need to remember this is not the last vote,” Goule said he was telling lawmakers.

With leadership staying mostly on the sidelines, much of the lobbying has been left to the farm groups, Lucas and Minnesota Rep. Collin Peterson, the top Democrat on the agriculture panel. On Tuesday, both said they think they had the votes for passage.

Peterson predicted at least 40 Democrats would support the bill. He too has been telling fellow Democrats that the food stamp cuts were likely to change in a conference with the Senate.

If the bill fails, he said, Congress will just have to haggle over another extension of current law. The 2008 farm bill was extended in January.

“If we can’t get this through now, I don’t know when we can,” he said.