New Zealand’s National Party is rejecting U.S. rapper Eminem’s claim that it has breached copyright rules for using the song “Lose Yourself” in a campaign ad.

On Tuesday, Eminem’s publishing company Eight Mile has filed complaint in High Court in Wellington against the political party for alleged copyright infringement of Academy Award-winning song, which the National used as a backing track for their election campaign ad.

The ad features background music that is similar to “Lose Yourself.”

Joel Martin of Eight Mile said that the 41-year-old Grammy winner wasn’t approached by National for permission to use the song.

“Eminem’s publishers were not approached for permission to use any of Eminem’s songs for this campaign advertisement,” Martin said.

“It is both disappointing and sadly ironic that the political party responsible or championing the rights of music publishers in New Zealand by the introduction of the three strikes copyright reforms should itself have so little regard for copyright.”

The company is seeking damages against National.

However, Prime Minister John Key’s political party has denied that it has broken any copyright law.

“The National Party purchased the music in question from recognised production music supplier Beatbox, based in Australia and Singapore. The music was originally published by Spider Cues Music, a well-established Los Angeles-based provider of music to the film and entertainment industry,” the National Party said in a statement.

“As with all works licensed by the Beatbox library music service, the National Party was assured the music in question did not infringe any copyright and was an original work,” the explanation continued, adding that the song was licensed multiple times in Australia and New Zealand without issue.

The statement further explained that the party has stopped using the music after the publisher contacted them.

“However, this has not satisfied the complainant.”

National Party said that it will be defending itself from the suit “vigorously.”

Eminem’s “Lose Yourself”