The National Party wants to stop former ministers who have just quit Parliament from being able to immediately become political lobbyists.
Former cabinet minister Kris Faafoi has started his own consultancy firm just months after quitting politics.
A move, he told RNZ last week, shouldn't have surprised anyone.
"I've spent the last 20 years in and around Parliament...so I don't think it's too out of the box thinking as to what I might've wanted to get into."
But National's Simeon Brown described it as an extraordinary situation.
"I don't begrudge Kris Faafoi for leaving Parliament and looking for another line of work, he's got to pay the bills and feed the family. But the reality is, he has had access to very significant information, sensitive information, he understands what his former colleagues think on various issues."
It is not unusual for former MPs and ministers to move into consulting after leaving politics, but many countries have what's called a "cooling off" period.
Australia makes its former decision-makers wait 18 months before they can start lobbying, while Canada has a five-year rule.
The National Party wants to see such a policy introduced here, although Brown didn't have a preference for how long the waiting time should be.
"This government has not been open and transparent. They should be taking a lead to address this issue, that will ultimately need to be led by the Cabinet Office to address what those guidelines should look like. National's willing to support that process."
A spokesperson for the Green Party said its MPs would also support a cooling-off period.
But ACT's David Seymour said such a measure would just force the lobbying underground.
"So long as it's clear whose meeting whom, for what purpose and when, in government, then I think that is okay," he said.
Prime Minister Jacinda Ardern made a similar argument.
She told Morning Report yesterday there was no need for change.
"Every New Zealander knows our policies by our manifesto," Ardern said.
"What's important is transparency. Ministers, when they meet ... we report through our pro-active diary release every single person that we meet with, we report on what subjects we meet with [them about].
"It is not voluntary - it must be reported as part of our official information Act proactive releases, which we've been doing since we've been in government."
Those diary releases show at least eight instances of former ministers, now-lobbyists, meeting with current ministers this year.
Five of those meetings were with Clayton Cosgrove, who was last a minister in 2008.
RNZ
