A fight nearly broke out in Parliament today over mandarins.
On one side was Labour Party MP Damien O'Connor, saying that shoppers were being lied to about where their fruit came from.
On the other was powerful Food and Grocery Council head Katherine Rich, who is strongly against making it compulsory for companies to say where their food is from.
Their war of words began when a select committee was shown pictures of mandarins, capsicums, and pears on New Zealand supermarket shelves which were marketed as being from New Zealand but were actually from Chile, the United States, Italy and the Netherlands.
"How can we trust a voluntary [labelling] scheme when your members are lying?" O'Connor asked Rich.
"I think that's very harsh and very unfair," she shot back.
"We have got photos - that's lying to the public," O'Connor said.
Rich said it was probably a mistake, and that her members were not responsible for supermarket signage.
"Are we seriously thinking that the poor supermarket worker who stacked that shelf set out to mislead the consumer?"
National MPs eventually intervened, saying O'Connor was out of line. Whanganui MP Chester Borrows said it probably a "cock-up" rather than a conspiracy.
"That is absolutely naïve," O'Connor said.
The argument came on a day when many of New Zealand's biggest companies lined up to oppose proposed changes to food labelling.
A bill in the name of a Green Party MP Steffan Browning would make it mandatory for all single ingredient foods including fruit, vegetables, fresh fruit, vegetables, meat, nuts, oils and flour to have country of origin labels.
Those in favour of a change say it is a simple measure which the public is strongly in favour of.
But a number of companies and lobby groups said today it was complicated, costly, and could undermine New Zealand's trading position abroad.
The National Party backed the bill at the first hurdle, but it could come under pressure to reverse its vote given the opposition from big business.
Federated Farmers national president William Rolleston said his organisation opposed labelling changes which did not relate to public safety.
Country of origin labelling would divert compliance officers from safety issues, he said.
Rolleston was also concerned about it could affect New Zealand's trade obligations, because it would undermine New Zealand's anti-protectionist position.
Fonterra director Philip Turner said his organisation was also opposed, because there was no consumer demand for dairy products to have better labelling.
Some business groups, however, were in favour of a change.
Pork New Zealand chairman Ian Carter said he supported the bill. The pork industry had been affected by a big increase in pork imports, which now made up around 58 per cent of the pork on supermarket shelves.
Under the current regime, consumers often couldn't tell local and foreign meat apart.
Advances in technology and IT meant label changes were not as costly as they were five or ten years ago, Carter said.
Former Green MP and activist Sue Kedgley said she was surprised about the food industry's opposition to country of origin labelling because it had overwhelming public support.
She said claims that a law change would "imperil our global trade" and raise food prices were "wildly exaggerated".
One of the strongest arguments for a law change was that it would support local producers.
"The garlic industry in New Zealand was on its last legs a couple of decades ago because the market was being flooded with cheap Chinese garlic that was slipping into the supermarkets unlabelled.
"And the consumers of course had no idea that the garlic they were buying was from China."
Consumer NZ presented the results of a recent survey, which said 71 per cent of New Zealanders supported a change, and just 9 per cent were against it.
Seven out of 10 were more likely to buy products if they were from New Zealand, the survey showed.