KEY POINTS:
The Engineering, Printing and Manufacturing Union is facing a further legal challenge over its bid to register as a third party to campaign in the election.
The National Party is expected to file papers today for a court challenge against the Electoral Commission's most recent decision to allow
the union to list as a third party.
The commission released its decision last week and was due to register the union last night after a seven-month delay while an objection to it because of the union's links with the Labour Party was considered.
However, it is again on hold after National told the commission it would try to have its decision overturned. It will also seek an interim court order to have the listing delayed until the court case can be heard.
National deputy leader Bill English said it would clarify the law. He said the commission's decision appeared to open the door for all organisations affiliated to political parties to run parallel campaigns.
EPMU national secretary Andrew Little said he was not surprised by National's challenge to the decision.
"We would rather focus on issues than legal tactics, but if that's what entertains them, let them go."
The EPMU's listing has been on hold since January after an objection from David Farrar, a blogger linked with the National Party, because of the union's close links and representation on Labour's internal bodies.
Under the Electoral Finance Act people and organisations involved in the administration of a political party are not eligible to list as a third party.
Last week the commission ruled the union was not involved in "administration" of Labour. Although Mr Little was on the governing council he did not represent the EPMU on that body. Mr Little said it would not affect the union's workers' rights campaign, which was issues-based. However, it would provide a safety net for the union.
Last night, the commission said it would list four other unions affiliated with the Labour Party whose applications were also on hold while the EPMU question was resolved.
However, it would further delay a decision on the EPMU until tomorrow to allow time to consider National's action.
The commission's first decision to list the union on the basis the law only referred to natural persons was overturned by the High Court, which said the term also covered organisations.