WASHINGTON — Top members of the United States House and Senate agriculture committees, as well as organizations representing American farmers, rallied against plans to cut federal crop insurance by $3 billion over ten years as part of a budget bill designed to raise the debt ceiling and avert a government shutdown.

“Farmers and ranchers have done more than their fair share to reduce government spending,” said Senator Pat Roberts of Kansas, chairman of the Senate Committee on Agriculture, Nutrition and Forestry. “To target the No. 1 priority for producers with additional cuts will undermine the delivery of this important protection for agriculture.”

Mr. Roberts, as well as Representative Mike Conaway of Texas, chairman of the House Committee on Agriculture, both said they would vote against the bill unless the planned cuts in the $9-billion-a-year crop insurance program are removed. Top Democrats on the agriculture panels also objected to the reduction in funds for crop insurance.

“This provision is opposed by an overwhelming majority of our committee members,” Mr. Conaway said. “It was debated and defeated during the 2014 farm bill process, and to move forward with it now breaks faith with the American producer.”

Other voices in agriculture such as the National Corn Growers Association and the National Association of Wheat Growers also registered their opposition to any planned cuts in the federal crop insurance program. The American Soybean Association said it “absolutely opposes any effort by Congress to reopen any part of the farm bill as part of budget negotiations,” arguing that farmers need a stronger safety net, not a weaker one, in the face of lower crop values and increasingly volatile weather.

The savings in crop insurance outlays proposed in the congressional budget deal would lower the rate of return for private companies selling crop insurance that depend on federal subsidies, which would be devastating to the industry, opponents contended.

The budget plan would raise the federal borrowing limit through 2017. The agreement was negotiated by the White House and congressional leaders, including House Speaker John Boehner of Ohio — whose last day in office is Oct. 30 — and was seen as likely to move to a floor vote in the House of Representatives as early as Oct. 28. Indications were that most House Democrats would vote for the bill. As many as 50 Republican votes also would be required for the legislation to pass before moving to the Senate, where proposed increases in defense spending were being welcomed by some influential Republicans such as Senator John McCain of Arizona.