This case could clarify how far companies can go when claiming their product is better than a competitor's.
In three years of pretrial litigation by both food-industry giants, thousands of pages of filings show the stakes are high.
Sara Lee made the first move in a 2009 lawsuit singling out Oscar Mayer ads that brag its dogs beat out Ball Park franks in a national taste test. Those tests, Sara Lee argued, stacked the deck against Ball Park, in part, by altering the way the hot dogs were cooked and served.
The lawsuit also contends Oscar Mayer touts its Jumbo Beef Franks as "100 percent pure beef," arguing that the claim is untrue, cast aspersions on Ball Park franks and damaged their sales.
Kraft defends the "100 percent pure beef" tag, saying its intent was to state that the only meat used is beef. Some industry hot dogs include a mix of turkey, pork, chicken or other meats. Kraft further argues that the "pure beef" label is justified because surveys show a perception among some consumers that hot dogs contain "mystery meats."
In 2009 Kraft filed its own lawsuit, alleging Sara Lee ran false and deceptive ads including a campaign where Ball Parks are heralded as "America's Best Franks." The ad further asserts that other hot dogs "aren't even in the same league."