WELLINGTON, New Zealand (AP) — The music publishers for American rapper Eminem are suing New Zealand's ruling political party over the music it used in a campaign commercial.

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

The National Party said in a statement that it would vigorously 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 disputed ad depicts a boat filled with people rowing together, symbolizing the party's unity.

New Zealand's general election is set for Sept. 20.