Washington state Attorney General Bob Ferguson on Monday sued to block the proposed merger of Kroger and Albertsons, two of the nation’s largest grocery chains.

In the suit filed in King County Superior Court, Ferguson argued that the $25-billion deal would harm consumers and raise prices, The Seattle Times reported. Kroger and Albertsons have more than 300 locations in the state and account for more than half of its grocery sales, according to the suit.

“This merger is bad for Washington shoppers and workers,” Ferguson said in a news release Monday. “Shoppers will have fewer choices and less competition, and, without a competitive marketplace, they will pay higher prices at the grocery store.”