Eminem is suing the New Zealand National Party for copyright infringement

In one of the best battles since the "halfway crooks" end rap battle from 8 Mile, Eminem is suing the New Zealand National Party over a 2014 ad which used a soundalike version of 'Lose Yourself'.

The National Party didn't whip the song up themselves of course, but purchased it from stock music providers BeatBox. They assumed copyright clearance was part of the BeatBox deal -- which is a fair enough assumption to make when purchasing stock music -- but the track was titled 'Eminem Esque', so it's unlikely nobody involved in the ad noticed the similarities. Talk about getting mum's spaghetti all over your face!

Eminem's lawyer Gary Williams called the Academy Award-winning 'Lose Yourself' "without doubt the jewel in the crown of Eminem's musical work", pointing that licensing of the tune is rare, and can "command in the millions of dollars. That's how valuable it is."

Still, the NZ National Party are denying any infringement took place, and it's hard not to barrack for defence lawyer Greg Arthur, who argued that copyright was "not in any way proven by the name given to a piece of music".

Check out the advert below, featuring the inspirational sounds of 'Eminem Esque', and then check out the bizarre video of a courtroom calmly listening to the famous hype up track.