Labour MP Chris Hipkins has been blasted for a lack of judgment over a question about New Zealand citizenship linked to questions about Australia's Deputy Prime Minister Barnaby Joyce's eligibility to be in Parliament.
Hipkins claims he didn't know the question, first put to him by a friend in the Australian Labor Party several weeks ago, was related to queries around Joyce's citizenship.
Had he known he says he might have given it a second thought, but Labour leader Jacinda Ardern says he shouldn't have got involved regardless.
Joyce's position in Australia's federal parliament will be examined by a court later this month after it was revealed he has New Zealand citizenship by descent through his father.
It was Hipkins' inquiry and questions from Australian media that led to the New Zealand officials notifying Joyce of his status.