Companies such as DaimlerChrysler, Omaha Steaks and ConAgra Foods Inc. have shared $1.5 billion in tax credits and refunds since 1998 under Nebraska’s Employment and Investment Growth Act. According to the state’s Revenue Department, those tax breaks created 72,000 new jobs. But the party might be over soon.

A lawsuit challenging the tax credits’ constitutionality may get the statute struck from the books. Filed in Lancaster County District Court in May, the suit alleges the tax breaks violate the state and federal equal protection clauses because they grant special rights and privileges to select corporations and individuals.