U.S. payroll legislation that prohibited the deduction of union dues from Michigan school employees' paychecks was recently blocked by a U.S. District Court judge who said the law may be unconstitutional.

The bill to enact the U.S. payroll compliance change, PA 53, was signed into law by the state's governor in March. Since then, it has been challenged twice. The latest argument is that it violates the 14th Amendment by treating school employees differently than other workers for no reason, The Detroit News reports.

"PA 53 singled out school employees for retaliation and does absolutely nothing to improve education for Michigan students," said David Hecker, president of AFT Michigan, the state affiliate of the American Federation of Teachers. Hecker called the law "unfair and punitive," as quoted by the news source.

As the Detroit Free Press notes, similar laws in other states have also been challenged in court. Earlier this year, a federal judge ruled that comparable legislation in Wisconsin violated workers' First Amendment rights.