The writer of the parody song 'Planet Key' feels vindicated by the Court of Appeal's decision finding the Electoral Commission was wrong to ban it.
Darren Watson's song - accompanied by a video by Jeremy Jones - was released on iTunes, YouTube and other internet platforms in the lead-up to the 2014 general election.
The Electoral Commission banned the song and an accompanying music video on the grounds that was an election advertisement, which meant it could not be played on radio, television or online without a statement declaring the singer-songwriter as its promoter.
Last year, the High Court overturned the ban - a decision that has now been upheld by the Court of Appeal.
The commission had challenged the High Court decision, saying there was a lack of clarity about how things were defined.
But the Court of Appeal rejected that bid, saying the commission should take a more rights-sensitive approach in assessments, and ordered it to pay Mr Watson's costs.
Mr Watson said he hoped no one else would have to go through the same experience and artists would be free to express themselves in the future.
The commission got it wrong by not using common sense to judge the item as merely a song and video for entertainment, he said.
The music video shows Prime Minister John Key in various scenes, including standing in oil-polluted water, playing a guitar made from a Māui dolphin, as an oil rig burns.
Mr Key said he didn't lose any sleep over the parody song.
He said he was not bothered by the findings as he always knew the song was a parody.
"Election campaigns always bring up these kinds of things. It's good to have the Court of Appeal ruling, because at least that way people understand what the rules are, but I didn't lose any sleep over the fact that somebody wrote a song about me that was slightly less than complimentary."