Eminem is taking New Zealand's ruling political party to court after claiming they used his song 'Lose Yourself' in a TV advert without permission.
The rapper accused the National Party of using an unlicensed version of the hit song in a 2014 campaign video.
Eminem's lawyer Garry Williams said the party breached copyright of a song owned by Eight Mile Style, Eminem's publisher.
Calling the song "iconic", Williams told the High Court in Wellington that rights to the work were "enormously valuable", since it had won two Academy Awards and two Grammys.
The campaign director for the National Party - led by Prime Minister Bill English - dismissed Eminem's claim when the row first erupted in 2014.
"We think it's pretty legal, I think these guys are just having a crack," Steven Joyce told reporters at the time.
Lose Yourself was the soundtrack to Eminem's 2002 film 8 Mile and went on to top the charts in 24 countries.
According to Williams, it deals with "the idea of losing yourself in the moment and not missing opportunities in life".
"That's why the song appeals to both the public and those who wish to influence the public by using it in advertising," he said.
He did not specify what damages they were seeking.
The party's lawyers will argue the tune used was not in fact Lose Yourself, but a generic track loosely based on it, bought from production music supplier Beatbox.
They are expected to contend that any copyright infringement was accidental in a judge-only hearing scheduled to last for six days.
Eminem is not the first artist to have complained about the unwelcome use of his tracks by a political party or candidate.
Just last year, the then presidential candidate Donald Trump came under fire by musicians such as The Rolling Stones, Adele, Neil Young, REM, Bruce Springsteen, Elton John, The Backstreet Boys and Queen.
The Backstreet Boys issued a statement distancing themselves from the I Want It That Way usage by the Trump camp, while the Stones asked Donald Trump to "cease all use" of their track Start Me Up "immediately".
Long before Mr Trump emerged as one of the least celebrity-backed candidates in US history, Ronald Reagan angered Springsteen by using Born In The USA in his election video - a stunt later repeated by President Trump and repudiated by "The Boss".
In the UK, Radiohead frontman Thom Yorke threatened to "sue the living s***" out of David Cameron in 2013 if he ever used any of their songs in an election campaign.
"I can't believe he'd like King Of Limbs [Radiohead's eighth studio album] much. But I also equally think, who cares? As long as he doesn't use it for his election campaigns, I don't care. I'd sue the living s*** out of him if he did," he said at the time.
Mr Cameron had already received a warning from former Smiths guitarist Johnny Marr after claiming to be a fan of the band.
"Stop saying that you like The Smiths," Marr wrote in response to Cameron.
"No you don't. I forbid you to like it."
It isn't just the Tory party that has been shunned by musicians - in 2008, James singer Tim Booth attacked Prime Minister Gordon Brown after the hit song Sit Down was played at the Labour Party conference.
A year earlier, Noel Gallagher hit out at Tony Blair for claiming to be an Oasis fan.