Eminem has taken New Zealand’s governing party to court over their 2014 campaign ad.

The rapper is suing the party after they used what he called ‘an unlicensed version’ of one of his biggest hits, Lose Yourself. Lawyers for the political party have fired back at those claims however, saying that the track was found on a stock music library, titled Eminem-esque. Court proceedings started today with the court listening to both the audio from the campaign ad and the 2002 smash hit. While Eminem was not present, his publishing group, Eight Mile Style, was represented by lawyers who said Lose Yourself was “iconic” and “without doubt, the jewel in the crown of Eminem’s musical work.” The 2014 campaign advert showed a team of rowers taking to the water, with the message ‘keep the team that’s working’ being said over the Eminem-esque soundbed.

Things I never thought I'd see - 9 lawyers plus a High Court judge listening to Eminem. 8-Mile Style vs National has begun.

— Katie Bradford (@katieabradford) April 30, 2017

The party claim they obtained the track from the music production company, Beatbox, who regularly feature songs that sound similar to famous tracks in their music libraries. Eminem’s lawyer, Gary Williams, said that its very rare that permission would be given to use Lose Yourself, saying that “when licensed, it can command in the millions of dollars. That’s how valuable it is.”

When National Party ad was being put together, the music brief was for an instrumental that was "edgy and modern", but still "dependable".

— Frances Cook (@FrancesCook) May 1, 2017

The National Party say they are not guilty of any copyright infringement, despite email proof of them raising concerns. The case is expected to continue throughout the week.