National MP Tim Macindoe called Winston Peters a "rat". The Deputy Prime Minister was quick to respond.

An urgent parliamentary debate on electoral law has devolved into insults and jeers as the NZ First Foundation donations scandal persists.

NZ First leader Winston Peters has called a National MP a "dysfunctional geriatric", after he was labelled a "rat".

The quarrelling in the House came on Wednesday morning, as parliamentarians were forced to urgently progress a change to electoral law through its final stages.

On Tuesday morning, Justice Minister Andrew Little announced he would urgently introduce the bill, which would ban foreign donations above $50.

ROBERT KITCHIN/STUFF Deputy Prime Minister Winston Peters entered the House on Wednesday morning to defend his NZ First party.

READ MORE:

* Government to ban foreign donations of above $50 under urgency

* Explainer: How New Zealand's convoluted electoral law works

* A wine box, a deep throat and a dumpster - the trail that led to the NZ First donations scandal

* 'I am the dark shadow of NZ First' - what party candidates claim Winston Peters' lawyer said

The bill passed after midday on Wednesday.

But the law does not address donations clouded by "foundations" associated with political parties.

NZ First is currently staring down a probe by the Electoral Commission, after Stuff broke a series of stories showing the party appeared to have used the NZ First Foundation to funnel undeclared donations into the party's election campaign.

On Wednesday, a group of National MPs was led by veterans Nick Smith and Gerry Brownlee in taking swings at the Government — despite their own party's support of the bill.

KELLEY TANTAU/STUFF National MP Tim Macindoe was called a "dystfunctional geriatric" by Winston Peters.

Peters, who entered the House to defend NZ First, said: "I'm very happy to tell us about the foundation, because it's based on the National Party's foundation."

National MP Tim Macindoe said many were asking why the Government was forcing through the legislation, and said some could "smell a rat".

"Clearly the rat is sitting over on that side of the House," he said while pointing at Peters.

Peters, in response, said: "I won't have the dysfunctional geriatric call me a rat."

MONIQUE FORD/STUFF National MP Gerry Brownlee says the electoral bill being passed under urgency will fix 'a $66 problem'.

National MPs cast the Green Party as the "major beneficiaries" of foreign donations, which they said averaged $66 each donation over the past seven years.

"We are here trying to solve a $66 problem," Brownlee said.

Smith tabled an amendment to the bill, which expands the definition of donations to include that from foundations associated with parties — which in theory could capture the NZ First Foundation.

This proposed amendment was voted down by the Government parties.

"If we are going to define a party donation, why not include the foundations? Why not include the obligation on New Zealand First?

"It is a rort that a secret foundation of New Zealand First at the last general election received $500,000 in donations," Smith said.

BRADEN FASTIER/STUFF National MP Nick Smith said the Government has its head in the sand over NZ First Foundation allegations.

NZ First MP Clayton Mitchell, who Stuff has revealed solicited for donations for the NZ First Foundation, at one point yelled at Brownlee to "open your books".

Brownlee labelled Mitchell the "bag man" for NZ First.

DONATION NUMBERS

The $66 average figure includes donations received by parties who no longer, or never were, voted into Government.

Of the parties in Government, a total $43,259.86 has been received through 534 donations — roughly $80 on average.

The Green Party has received the most foreign donations since 2011, at 419, and the second-most by amount at $15,033.

National received the most in foreign donations, $20,080, which included $17,180 in 2017.