Former New Zealand First MP Brendan Horan insists he has done nothing wrong and will stay on in Parliament as an independent and contest the next election.
The MP was expelled from the party's caucus last week after its leader, Winston Peters, said he had received information that caused him to lose confidence in his MP.
Under the party's constitution, Mr Peters is not able to terminate someone's membership. The party's board issued a statement following a meeting on Monday saying that Mr Horan had relinquished his membership.
Mr Horan rejects allegations of overusing his parliamentary phone for TAB betting, saying he made 14 calls a month, not 12 a day as has been alleged.
He told Radio New Zealand's Morning Report programme that he was most concerned about his telephone documents being leaked to the media. "They had people's telephone numbers on, people who had rung me in confidence with massive problems. Their confidence has to be guaranteed."
New Zealand First leader Winston Peters said there is no evidence that he or his office leaked the parliamentary phone records of Mr Horan to the media. Mr Peters said he assumes the leak came from Parliamentary Service, and he was not responsible. The Parliamentary Service has declined to comment.
Mr Horan refused to discuss allegations about his mother's will, saying that is a private matter and is being worked through with his lawyer.
Prime Minister John Key says it's still unclear to him whether the former New Zealand First MP should still be in Parliament. Mr Key says in the past he has not been afraid to say when he thought an MP should leave Parliament, but finds it hard to assess this case, and it is time for the Winston Peters to lay out his reasons for expelling Mr Horan.