Milwaukee ? Hot dog sales are set to sizzle as people look for ways to eat on the cheap and the summer grilling season starts. But the scramble to be top dog in the $2.1 billion market has sent the makers of Ball Park franks and Oscar Mayer wieners to court.

The lawsuit focused on advertising and product claims filed this week by Sara Lee Corp., the maker of Ball Park Franks, against Oscar Mayer-making rival Kraft Foods Inc.

The stakes are big as the peak season for franks begins this weekend — 38 percent of hot dog sales each year occurring between Memorial Day and Labor Day.

Sales had been fairly stagnant in the past few years. But revenue in the category rose 5.3 percent to $2.1 billion in the 52 weeks ended April 18. Part of that was due to higher prices.

Sara Lee and Kraft are continually battling to be top dog, and store brands are now gaining market share. Private label dogs used to be in the top 10 as far as hot dog sales but now they’re in the top five.

Sara Lee and Kraft are embroiled in a lawsuit. Sara Lee alleges that Oscar Mayer’s claims that its Jumbo Beef Franks are “100 percent pure beef” are false and hurting sales of Ball Park franks and the brand’s reputation, according to the suit filed in the U.S. District Court for the Northern District of Illinois.

Sara Lee also questions ads claiming that Oscar Mayer wieners outperform Ball Park and Hebrew National hot dogs, made by ConAgra Foods Inc., in taste tests. The company is asking for corrective advertisements and damages.