US dairy farmers are blaming a low-cost milk powder for diluting their business and misleading consumers.

Milk Protein Concentrate, MPC, is a highly filtered form of dried milk protein that is imported to make cheese products at a lower cost and with less milk.

Many farmers blame the lack of restriction on imports of MPC for the current low milk prices. William Underwood, a dairy farmer in Tully, New York, said he has not seen dairy prices so low since the late 1970s. “It’s affected all dairymen in the United States, and it hurts us, because some of the major cheese companies like Kraft are making a cheaper product by using it,” said Underwood. “Some of the countries that make it don’t have the same sanitary regulations and requirements we do here.”

The farmers have the support of some lawmakers to impose tariffs on MPC imports, but not enough to pass the legislation.

Last month the Food and Drug Administration sent a written warning to US food giant Kraft Foods about its use of MPC in its American cheese singles slices and Velveeta without proper labelling on the package.

Kris Charles, a spokeswoman for Kraft, said MPC has been used for more than 20 years in the food industry and has become a “convenient scapegoat” for milk prices that are falling for other reasons such as overproduction and waning demand.

Charles added that Kraft was hoping to find a domestic producer of MPC soon, reported the Associated Press.