OKLAHOMA CITY (AP) — Oklahoma's new $1.50 fee on a pack of cigarettes is an unconstitutional "tax," cigarette companies and three Oklahoma residents say in a lawsuit asking the state Supreme Court to prevent it from taking effect.

The lawsuit, filed Wednesday by Phillip Morris USA Inc., R.J Reynolds Tobacco Co. and others, alleges the fee violates a state constitutional prohibition against passing revenue-raising measures in the final five days of a legislative session and without a supermajority of lawmakers.

Oklahoma Attorney General Mike Hunter said Thursday his office was reviewing the law...