KEY POINTS:
Lawyers for the Electoral Commission says the court should not intervene lightly in the commission's decision to allow a major union to campaign officially in the lead up to the election.
Commission lawyer Peter Gunn said the court should take a "very conservative approach" when deciding on the
National Party's challenge to the decision to allow the Engineering, Printing and Manufacturing Union to become a third party.
The case was heard in the High Court at Wellington yesterday - and the outcome will have ramifications for other groups which are formally associated with political parties.
Mr Gunn urged the court to be careful, saying the commission was an independent, expert body which was "a cornerstone of the democratic process", and previously courts had been reluctant to intervene.
"The political nature of the decisions the Electoral Commission is called upon to exercise are factors that in this case should make courts reluctant to intervene in the commission's discretion."
He said National was asking the court to replace the commission's "value judgments" with its own - which was not the role of the court.
But National Party lawyer Peter Kiely said the commission's decisions should be challenged where it had not applied the law properly.
He said it had used an overly narrow interpretation of what it meant to be involved in the "administration" of a party's affairs and had not taken crucial information into account.
Mr Kiely said the commission took EPMU national secretary Andrew Little at his word over his and the union's involvement in the Labour Party without seeking other information - including the union's own constitution.
It had "materially understated" the role of the EPMU within the Labour Party and the consequence was not only a "grave" error which went against the intent of the act, but also prejudiced the National Party.
"The [EPMU] will be able to run a campaign similar to the campaign that they ran at the 2005 election which will attack the [National Party] and will be doing so despite not lawfully being allowed to do so."
Mr Kiely also rejected its decision that Mr Little did not act under the union's direction in his post as affiliates vice-president on Labour's governing council.
He said Mr Little was in the post because of his position on the union, rather than in his own right. Further, the union's constitution said he must act under the direction of the executive when required.
In reply, David Ginn said the commission had the discretion to consider which material it believed relevant, and in this case had considered Labour Party rules on the involvement of the union.
He said according to those rules, Mr Little's role as vice-president was in his personal capacity, rather than as a union representative.
Justice Alan MacKenzie reserved his decision.