The woman who accused Labour MP Trevor Mallard and a top public servant of destroying her reputation has won an appeal to the Supreme Court.
In 2007, whistleblower Erin Leigh accused Mallard, then Environment Minister, of defamation.
This was after she raised questions about political interference and alleged former minister David Parker pushed for Clare Curran to be appointed to a communications role with the Ministry.
All three Labour members involved are currently sitting Members of Parliament.
At the time Mallard was asked an oral question on the matter in Parliament and spoke negatively about Leigh.
He told the House she had "repeated competence issues" and said Curran had been appointed to "fix up the mess".
The Ministry's then Deputy Secretary Lindsay Gow had been appointed to provide Mallard with written and oral briefings before he answered the question.
Unable to sue Mallard, who was protected by parliamentary privilege, Leigh subsequently sued Gow for defamation.
Gow contended that his written and oral communications to the minister were also covered by absolute privilege and that the claims should therefore be struck out.
But the High Court, Court of Appeal, and now Supreme Court ruled that it was a matter of qualified, not absolute, privilege.
Absolute privilege prevents politicians from being sued for what they say in the House.
They have no legal liability for what is said in the House. That means they cannot defame anyone or face legal repercussions as a result of what they say during parliamentary proceedings.
Qualified privilege applies to fair and accurate reporting of parliamentary proceedings and means a person cannot be liable for defamation for repeating what was said under absolute privilege, unless they do so with ill intent.
This is the provision that protects media reporting on events in Parliament.
In its decision released today, the Supreme Court found Gow's interaction to be covered by qualified privilege but said he could not face a defamation claim unless Leigh could prove he acted with ill-will.
"The issue is whether the public servant, or whoever else communicates information to the Minister, needs more than qualified privilege in order to enable the Minister, and the House as a whole, properly and efficiently to deal with parliamentary questions."
The Court found that was not necessary and said it was a "no bad thing" that public servants were prevented from acting with ill-will when advising a minister.
"It is very much in the interests of the proper functioning of the House that those communicating with a Minister in present circumstances, whoever they are, have a disincentive against giving vent to ill will or improper purpose."
Leigh today refused to comment on the matter saying it would be inappropriate to do so while the legal proceedings were ongoing.
Mallard also refused to comment.
Parker and Curran could not be reached for comment.
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