Bayer, the beleaguered maker of Roundup herbicide, has garnered the support of the US Department of Justice in its court battle to turn back a tide of litigation brought by people claiming the company failed to warn them of cancer risks associated with the weed killers.

In a Dec. 1 filing with the US Supreme Court, Solicitor General D. John Sauer, appointed by the Trump administration in April, told the court that it should take up an appeal from Bayer that the company hopes could help it quash ongoing lawsuits inherited when it bought Monsanto in 2018.

Bayer, which maintains its glyphosate herbicides do not cause cancer, argues that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which governs the registration, distribution, sale, and use of pesticides in the United States, preempts “failure-to-warn” claims against the company. Because the Environmental Protection Agency (EPA) has approved labels with no cancer warning, failure-to-warn claims should be barred, the company maintains.

Multiple courts have rejected Bayer’s argument, including two appellate courts, ruling that FIFRA does not preempt failure-to-warn claims, though one appellate court – the Third Circuit Court of Appeals- has sided with Bayer.

A similar effort by Bayer to get the high court to weigh in on the preemption issue was rejected in 2022 after the Biden administration’s Solicitor General asked the high court not to hear Bayer’s appeal on the same issue, saying that “FIFRA does not preempt” such claims.