Prime Minister John Key says Brendan Horan’s expulsion from New Zealand First's caucus has highlighted public frustration with MMP.
Both Mr Horan and party leader Winston Peters were absent from Parliament this afternoon.
The Tauranga list MP has been given two days leave from Parliament, after he was expelled from the party caucus amid allegations of a misappropriation of funds.
Mr Key says while he does not understand all the facts, he took a swipe at MMP, saying justice minister Judith Collins’ review of MMP is timely.
Mr Key says there is some "public frustration" with MPs who enter parliament under the coat tails of a party, then get removed from the party's caucus but remain in parliament.
NZ First's board meets tonight to deal with ousted MP Brendan Horan's party future.
A senior political figure says the board will do what Mr Peters tells them to do but party president Kevin Gardener already appears to be hedging his bets.
In one breath, Mr Gardener says allegations against Mr Horan are "hearsay" but then says leader Winston Peters, a former lawyer, and other MPs "would have done their homework".
Mr Gardener told NBR ONLINE there are no formal motions for consideration during tonight's internet Skype call.
"It's just, hey, this has happened, where do we go forward from here.
"Until things have been presented to us there can't really be a resolution.
"But there again it's all hearsay at the moment, isn't it?
He says Mr Peters – who sits on the board – has not yet divulged the evidence which led him to fire Mr Horan from NZ First's caucus.
'They would have done their homework'
There are allegations within Mr Horan's family that money has been taken from his dying mother's bank account.
A university academic says Mr Horan can be ejected from NZ First but not parliament, unless he resigns of his own volition or is convicted of a serious offence.
Nelson-based Mr Gardener says Mr Peters is one of two lawyers amongst the party's MPs and "Winston will have seen stuff that he believes in".
"They would have done their homework.
He says it is hard it has happened but says "there's nothing you can do about it."
"People say you can't check out your candidates but an alcoholic never tells you they're an alcoholic, do they?"
Mr Gardener says the process dealing with Mr Horan's party membership will be "very slow".
NZ First leader Winston Peters is powerless to remove Brendan Horan from parliament, a politics academic says.
Massey University associate head of politics, associate professor Richard Shaw, says party membership is the vehicle by which someone is elected to parliament, but once there parliament's constitutional right to control its members trumps that of political parties.
"He's come in on the NZ FIrst party list but the party doesn't have the statutory right to expel him from the parliament.
"It can expel him from the caucus and then he can be expelled from the party, but NZ First as a political party can't tell parliament what to do with its own members.
"The politics of this are awkward for NZ First and a distraction."
Mr Horan was expelled from the party caucus yesterday and Mr Peters called on him to resign as an MP, over family allegations relating to money apparently missing from his dying mother's bank account.
Under the Electoral Act 1993, Mr Horan is most likely to vacate his seat if he resigns or if he's convicted of a crime punishable by a prison term of two years or more, Dr Shaw says.
Before 2005 – when the so-called waka-jumping legislation expired – Mr Horan would have had to leave parliament if expelled from NZ First.
NZ First board can initiate own inquiry
Mr Horan's lawyer Paul Mabey QC says the list MP is contemplating an appeal to the party board to allow him to stay.
NZ First's constitution says membership can be terminated if the person's conduct is "offensive, undesirable, inconsistent with the welfare and interest of the party, or contrary to the constitution".
The party's board holds a hearing to investigate a written complaint about the member, or it can initiate its own inquiry.
The member must be notified within 14 days of receiving the complaint and the member can be present and heard at the hearing.
Punishment ranges from a censure to expulsion.