"For over two years the USDA has been unable to purchase canned tuna for federal nutrition programs," Sanchez said in a statement to The Hill.

"Moms across the country know that tuna is a lunchtime favorite and a great source of protein for growing children," she said. "Our legislation will strengthen the USDA's ability to purchase canned tuna."

Under current law, all tuna to be used in federal nutrition programs must be caught by U.S.-flagged vessels, cleaned and processed in the United States, and canned either in the United States or U.S. territories.

But those tight restrictions have made it tough to find tuna that qualifies for purchase. Sanchez's bill would relax the rules to allow up to 25 percent of the tuna bought by the government to be cleaned and processed outside the United States.

"The Tuna Competition Act will not only make tuna available for school lunch, child nutrition, and other nutrition programs, but this legislation will also help the U.S.-based tuna industry," Sanchez said.