PITTSBURGH — The Pittsburgh City Council has voted to levy a 10 percent excise tax on billboards, but Baton Rouge outdoor advertising company Lamar Advertising says it will fight the plan in court.

The council on Monday voted 7-2 to impose the tax. The city says the tax could generate up to $4 million annually.

But an attorney for Lamar Advertising said billboards are protected under the First Amendment.

Jonathan Kamin said Lamar will sue in federal court if the bill gets final approval next week.

Last month, Lamar used area billboards to criticize council members who proposed the tax.