HOUSTON -- A coalition of Houston bars and nightclubs has filed a federal lawsuit challenging a city ban on smoking in most bars.

The City Council approved the ban in October and it's set to take effect next month.

Members of the Houston Association of Alcoholic Beverage Permit Holders claim the ordinance is unfair because it allows smoking in cigar bars and other bars that derive significant revenue from tobacco sales.

The lawsuit claims the city doesn't have the authority under state law to create different regulations among businesses licensed to sell alcohol for on-site consumption.

The bars want the court to stop enforcement of the ordinance.

City Attorney Arturo Michel says Houston's ordinance is legal. He says various bars are not being treated differently in terms of alcohol. He says the rule regulates smoking in a range of public places.