Both of Iowa’s U.S. senators say consumers and producers could be hurt if Smithfield Foods is allowed to buy Premium Standard Farms in a proposed 810-million dollar deal.

Smithfield is the nation’s top hog producer and processor while Premium Standard is a close competitor. Senator Chuck Grassley says the merger could give Smithfield too much control of the market.

Grassley says he doesn’t like the buyout and has asked the U.S. Attorney General to look into the matter. Senator Tom Harkin has joined Grassley in calling for a Justice Department probe as Harkin says the merger could violate federal antitrust regulations.

Grassley agrees, saying “One of the strong points for the benefit of American agriculture is to make sure there’s plenty of competition, and on first blush, particularly considering Smithfield was already a dominant force, taking on Premium Farms is just one more point of a reduction of competition which bothers me very much.”

The buyout would reportedly give Smithfield control of one-fifth of the nation’s pork production and nearly one-third of the pork processing.