KANSAS CITY, Mo. (AP) — A group of business associations has started a petition drive to try to force a referendum election aimed at overturning Kansas City's new minimum wage law. The Kansas City Star reports that the group has until August 25 to gather about 3,400 signatures to challenge the measure recently approved by the City Council. The measure raises Kansas City's minimum wage from $7.65 per hour to $8.50 per hour on August 24, with annual increases to $13 per hour by 2020. The group, Missourians for Fair Wages, includes restaurant, hotel and other business associations. Spokesman David Jackson says the group wants to slow down the city action to make sure it doesn't hurt the local economy. Minimum wage increase proponents condemned the group's effort and said they'll fight the petition drive.