Kroger and Albertsons will defend their merger plans in a hearing in federal court in Oregon that is scheduled to begin Monday – and try to overcome the objections of the U.S. government.

The two companies have proposed the largest supermarket merger in U.S. history in October 2022. They say the merger would help them contain costs and better compete with major rivals such as Walmart and Costco.

But the Federal Trade Commission (FTC) tried to block the deal, arguing that it would eliminate competition and raise food prices at a time of already high food inflation. The commission also claimed that quality would suffer and workers’ wages and benefits would decrease if Kroger and Albertsons no longer competed with each other.

The FTC is seeking a temporary restraining order to block the merger while its lawsuit is heard by an internal administrative law judge. In a three-week hearing set to begin Monday, U.S. District Judge Adrienne Nelson is expected to hear from about 40 witnesses, including the CEOs of Kroger and Albertsons, before deciding whether to issue the temporary restraining order.

The attorneys general of Arizona, California, the District of Columbia, Illinois, Maryland, Nevada, New Mexico, Oregon and Wyoming joined the lawsuit on the FTC’s side.

Kroger, based in Cincinnati, Ohio, operates 2,800 stores in 35 states, including brands such as Mariano’s, Ralphs, Smith’s and Harris Teeter.

Albertsons, based in Boise, Idaho, operates 2,273 stores in 34 states, including brands such as Safeway, Jewel Osco and Shaw’s.

Together, the companies employ around 710,000 people.