Senator Chuck Grassley of Iowa, a senior Republican on the Agriculture Committee, said that if all else fails Congress will extend the current law.

“If the White House is willing to back off of food stamps, we’ll have a farm bill before Christmas,” Grassley said. “If not, there will be an extension of the current bill.”

On taxes, Congress faces pressure to extend more than two dozen credits and deductions that have lapsed or are nearing expiration. Negotiations will hinge on the cost of the package and balancing the tax breaks between red and blue states.

Biofuel credits -- favored by farm state Republicans -- and a $7,500 credit for electric-car buyers -- backed by Democrats -- are among the benefits up for renewal. The expiring tax breaks also benefit racehorse owners, miners and railroad companies.

Republicans also want to fix a mistake in the 2017 tax overhaul that forces restaurants and retailers to wait almost four decades to recoup the full cost of renovations. Drafters had intended to let them write off the costs immediately.

Democrats, who unanimously opposed the tax cut, are reluctant to help the GOP rectify its errors. But Schumer said he could support tax-code fixes if they also include benefits favored by Democrats such as larger credits for low-income workers or affordable housing.

Criminal Sentencing
Congress also may consider revising criminal sentencing laws, although GOP leaders say that may be pushed into 2019 without quick signs of agreement.

The House in May passed a prison measure providing $50 million annually through 2023 for programs aimed at curbing recidivism. But the bill has been held up in the Senate, where Grassley, the Judiciary Committee chairman, wants to include sentencing changes his panel approved in February.

Grassley wants to give judges more leeway in sentencing, reduce mandatory minimum terms for some low-level nonviolent offenses and retroactively apply a federal law that reduces sentence disparities between crack and powder cocaine offenses.

Meanwhile, additional sanctions on Russia could be on the agenda, but also may be punted into 2019.