Washington (CNN) -- Backers of a comprehensive new farm bill held a campaign-style rally Wednesday on Capitol Hill, cranking up the political heat on House Republican leaders struggling to balance competing election year and ideological pressures.
"All of us gathered here today ... share one common and resounding message," said Bob Stallman, head of the American Farm Bureau Federation. "Congress, for our farm and ranch families, their communities and for our nation, pass the farm bill now."
Stallman was cheered by a boisterous crowd at the Capitol Reflecting Pool.
"We are out here to let our congressmen know it is important that they pass the farm bill," Julie Taylor, an independent voter from Indiana, told CNN. "It is frustrating. ... Knowing that we don't know what to do or what to plan for is very difficult."
House Majority Leader Eric Cantor, R-Virginia, told CNN the House Republican leadership is still "working with the Senate to see what can be done." He conceded, however, that the "timing is definitely short."
Kevin Smith, a spokesman for House Speaker John Boehner, R-Ohio, said he hopes the Senate will pass a livestock disaster aid bill previously approved by the House. He stressed that "we are still discussing options on a farm bill extension."
The current five-year law establishing various levels of federal support for drought-stricken farmers and ranchers expires September 30.
While the Democratic-run Senate passed a $969 billion replacement bill in June through a rare bipartisan 64-35 vote, numerous conservatives in the Republican-controlled House have balked at the overall price tag and spiraling cost of food stamps included in the measure.
"For conservatives like myself ... the real concern (is) that what is now a farm bill is really not that. It's a food stamp bill," said Rep. Tim Huelskamp, R-Kansas.
Farm Belt Republicans in tight political races this fall, however, are pushing hard for quick legislative action on a more traditional comprehensive deal.
North Dakota Rep. Rick Berg, a freshman House Republican seeking to replace retiring Democratic Sen. Kent Conrad, said Wednesday his message to the House Republican leadership is simple: Get it done.
"We've got to get this done," Berg told CNN. "This is what's wrong with Washington."
Berg refused to speculate about possible repercussions for his campaign if the House fails to act.
"This is about the farmers and ranchers in North Dakota," he said. "The last thing we need to do is create this cloud of uncertainty that will happen if we don't get a long-term farm bill done."
The congressman expressed optimism that the House will be able to act over the next few weeks.
"In the legislative process they work best under deadline, and so I just think we need to keep pushing right now," he said.
South Dakota Rep. Kristi Noem, a first-term Republican, told reporters at the rally she is "disappointed" that House GOP leaders haven't scheduled a floor vote on another five-year bill approved by the House Agriculture Committee. The committee's bill is broadly similar to the Senate plan.
"That has been a big disappointment for me," she said.
Noem and Rep. Peter Welch, D-Vermont, sent a letter to Cantor on Wednesday requesting a meeting to discuss the possibility of bringing a bill to the House floor for a vote by the full chamber.
"Whether members support or oppose the farm bill, we believe the House should be allowed to vote so that we can be held accountable to those we represent," the letter said.
While the full House has supported short-term drought disaster relief, several prominent Democrats and Republicans have expressed concern about the economic fallout that may accompany a failure to enact a new long-term deal.
"If the farm bill is allowed to expire and things begin to unwind, we turn back the clock in rural America," said Michigan Democratic Sen. Debbie Stabenow, head of the Senate Agriculture Committee and primary author of the Senate plan.
Agricultural markets, Stabenow declared at the rally, would be in "disarray" without a comprehensive new law.
"It's absolutely crazy to even get close to something" like that scenario, she said.
Minnesota Rep. Collin Peterson, the top Democrat on the House Agriculture Committee, told the crowd more grassroots pressure will be needed in order to force the GOP leadership's hand before the end of the current Congress.
So far "the groundswell is not out there," he warned. "This rally is a good starting point but what we need, what is going to change this, we need 100 or 200 calls from people in their districts to these members. That's what is going to change this."
"If you don't do that, we're not going to get a farm bill," he said. "It's that simple."
A number of conservative leaders want to wait until after the November election, at which point they hope full Republican control of Congress and the White House will allow them to draft a bill more in line with their ideological preferences.
Rep. Tom McClintock, R-California, argued Wednesday that Congress "shouldn't be subsidizing any product."
"It has nothing to do with how much they're making or not making," he said at the panel discussion with Huelskamp. "Prices convey an enormous wealth of information that is absolutely essential to consumers to make rational decisions in the marketplace."
For their part, top Senate Republicans have indicated support for a short-term extension if the Senate's five-year bill can't get through the House.
"I represent a state in which agriculture is important," Senate Minority Leader Mitch McConnell, R-Kentucky, said Tuesday. "I don't believe that we ought to let the current farm bill expire if we're unable to at this point to pass a replacement."
The head of the House Agriculture Committee, Oklahoma GOP Rep. Frank Lucas, told CNN on Wednesday "there's a growing probability" that a one-year extension is "the most practical thing."
"I believe some kind of action will happen before we go home (for the campaign), and it's my intent to help to make it happen," he said. "Something has to happen."
CNN's Ted Barrett and Deirdre Walsh contributed to this report