WELLINGTON, New Zealand (AP) — The music publishers for American rapper Eminem filed a lawsuit yesterday against New Zealand’s ruling political party over the music it used in a campaign commercial.

Detroit-based Eight Mile Style and Martin Affiliated both claim the National Party breached copyright laws by using Eminem’s song Lose Yourself. Joel Martin, a spokesman for the two companies, said they filed a case in the New Zealand High Court and are seeking damages.

“It is both disappointing and sadly ironic that the political party responsible for championing the rights of music publishers in New Zealand… should itself have so little regard for copyright,” Martin said. “We do not hesitate to take immediate action to protect the integrity of Eminem’s works.”

The National Party said in a statement that it would vigourously defend the action. It said the music it used was originally published by Spider Cues Music in Los Angeles and sold to it by an Australian-based supplier.

“The National Party completely rejects the allegation that the library music used in its early campaign advertisements is a copyright infringement of any artiste’s work,” the party said.

It said that, nevertheless, it had undertaken two weeks ago not to use the music anymore.

“However, this has not satisfied the complainant,” the party added.

Martin said the publishers have previously sued Apple for using an Eminem song in an ad without permission and have been in a dispute with Audi over alleged infringing use of Lose Yourself.

The disputed ad in New Zealand depicts a boat filled with people rowing together, aimed at symbolising the party’s unity.

New Zealand’s general election is set for September 20.