WASHINGTON – The Senate is seeking to reverse a controversial law that allows farmers to harvest genetically modified crops even when the crops are caught up in legal battles.

The law, passed as part of a spending bill earlier this year, has become a flashpoint in the national debate over genetically engineered foods. It would expire at the end of the federal budget year next week, and a temporary spending bill passed by the House would extend it. But Senate Democrats’ spending bill would let it expire.

The narrow provision only applies to genetically modified crops that are under litigation. It allows the agriculture secretary to grant permits for farmers to continue to grow engineered crops while appeals are pending, even if courts have ruled that the Department of Agriculture shouldn’t have approved them.

The provision’s supporters say it is designed to help farmers weather the sometimes yearslong appeals process and avoid stops and starts in planting as courts reverse each other’s decisions. Genetically modified seeds, especially those engineered by seed giant Monsanto, have been the subject of several lawsuits by environmentalists in recent years, often putting farmers who use them in a bind.

Monsanto and several major farm groups backed the provision, and it soon became a rallying point for activists who oppose genetically engineered crops. They dubbed it the “Monsanto Protection Act,” a title that stuck and was even used by Democratic opponents of the measure on the Senate floor.

“It raises profound questions about the constitutional separation of powers and the ability of our courts to hold agencies accountable to the law and their responsibilities,” said Sen. Jeff Merkley, D-Ore., during debate over a wide-ranging farm bill last summer. “This process and this policy has provoked outrage across the country.”

Agriculture Secretary Tom Vilsack similarly questioned the proposal, saying he believes that he already has the power the law gives him. Referring to the backlash against the provision, he said in May that the law created confusion and suggested that it made it harder to find compromise.