who express personal political views via media other than the internet, and such over-inclusiveness is for Parliament to remedy. [69] We also differ in some respects from Mander J in Greenpeace. He held that effect must be gauged by taking an objective view of the facts, partly because he reasoned that a purposive approach would create uncertainty by seeking to distinguish issue advocacy from election advertising.64 We agree that the test is objective and may capture issue advocacy where it sufficiently identifies party or candidate positions and encourages voting by reference to them. But the legislation must be applied purposively, recognising that it is aimed at participants and parallel campaigners, and from the perspective of the reasonable observer who is sensitive to the importance of free political speech, and in a manner that protects the expression of personal political views. This requires that difficult judgments be made at the margin, but the difficulty is unavoidable. It is why the legislation confers upon the Commission a substantial measure of discretion in the exercise of its advisory and policing functions. The song and video were not election advertisements [70] In our opinion Messrs Watson and Jones plainly were not parallel campaigners. There was no public interest in knowing who they were; they represented no group or vested interest whose identity voters might want to know when assessing the song and video. They were simply expressing their own political views. And although Mr Watson incurred production costs that would fall into the definition of advertising expenses, they were not substantial. [71] As noted, the respondents conceded that the song and video were likely to encourage voters not to vote for Mr Key or the National Party. Nothing now turns on it between the parties, but because this judgment will guide the Commission and others in future we record that we do not wish to be seen to adopt this concession. We add that the facts of Greenpeace are not before us and we express no view about whether the climate voter website had the required effect upon voters. 64 Greenpeace of New Zealand Inc v Electoral Commission, above n 2, at [46]–[60].