The Missouri Supreme Court has rejected a legal challenge to a voter-approved law that requires periodic elections to decide whether to keep municipal earnings taxes.

Missouri voters in 2010 approved a statewide ballot measure requiring Kansas City and St. Louis to hold an election to decide whether to keep their municipal earnings taxes, with subsequent public votes every five years on whether to keep the tax.

Two Kansas City leaders filed a lawsuit challenging the voter-approved measure. They argued it wrongly required an election without providing funding and improperly amended Kansas City’s charter. The high court rejected the claims in a unanimous opinion Tuesday.

Voters in Kanas City and St. Louis supported keeping their earnings taxes in the first election required by the voter-approved law.