An overwhelming majority of New Zealanders oppose list MPs staying in Parliament if they leave their party, prompting new calls for legislation to prevent "waka-jumping".

The latest Fairfax-Ipsos political poll found only 14.9 per cent of New Zealanders believed list MPs who were no longer part of their party should be allowed to remain in Parliament.

More than three-quarters - 76.1 per cent - said independent list MPs should not be able to stay on, while 9 per cent did not know.

The issue has been in the news after Brendan Horan was kicked out of the NZ First caucus, following claims he may have spent his late mother's money without her knowledge. Mr Horan has denied any wrongdoing.

This month National Party MP Aaron Gilmore resigned from Parliament in the wake of a storm which started after a dispute with a barman in Hanmer Springs.

However, before he quit, Prime Minister John Key admitted there was little that could have been done to force Mr Gilmore from Parliament if he refused to resign.

Almost every demographic appeared to oppose list MPs staying on if they left their party, although older voters were more opposed than younger voters.

Only 51.5 per cent of voters aged under 30 opposed the MPs staying on compared with 90.2 per cent of voters aged over 65.

NZ First leader Winston Peters is calling on Parliament to back a bill to prevent so-called "waka-jumping" which his party is proposing, especially National, after Mr Key indicated there may be a need for the legislation.

"The public is seriously against this sort of behaviour, and frankly, Parliament should be responding to it," Mr Peters said.

While he accepted that the legislation could add to the risk of "despotic" behaviour by a party leader, that party would face a possible voter backlash at the next election.

"The public can be trusted to decide whether a party has acted appropriately or not," he said.

Mr Horan said the idea "superficially sounds good" but did not stand up to scrutiny and could harm democracy.

"What happens when you've got someone who's rising in popularity within their own party and when some manufactured crisis comes along, the leader is concerned about his position, and he kicks that person out of caucus," Mr Horan said, adding that this was "a scenario" and not his personal situation.

Mr Key has expressed support for the idea of legislation but is not rushing to support Mr Peters' legislation.

"There is potentially the need for legislation regarding 'waka-jumping' but it's a very complex area and not a priority for the Government," a spokeswoman said.