HELENA, Mont. -

An attorney and legislative candidate from Bozeman is challenging a state law that requires candidates to be thorough and accurate when portraying an opponent's voting record in campaign materials.

The Montana Legislature passed a bill in 2013 that requires any printed material that mentions an opponent's voting record to include a reference to all the votes upon which the information is based, a disclosure of contrasting votes known to have been made by the same candidate over the past six years and a signed statement that the information is accurate.

Lee Newspapers of Montana reports Matthew Monforton filed a lawsuit last week asking a federal judge to temporarily block enforcement of the law, saying it burdens his free speech and is unconstitutionally vague.

U.S. District Judge Dana Christensen has set a hearing for Feb. 7 in Missoula.