UPDATED 1.11pm: Andrew Little says another bad season for dairy farmers could cause New Zealanders to lose some of the country's best agricultural land to offshore buyers.

The Labour leader said Fonterra had offered interest-free loans to some struggling farmers.

On the Q&A programme, he said banks had told him they'd help farmers for one tough season, but beyond that there were uncertainties.

"There is a crisis in dairy...we do have some tough times ahead."

He told TV One a combination of the Government, farmers and banks needed to work together to address the problem.

Mr Little said "the biggest threat" to farmers would arise when they couldn't even afford to keep their land.

He said if dairy farmers had to start selling land, people with the money to buy that land would be offshore buyers, such as the Americans and Chinese.

The Labour leader said a regional development plan was needed to help the provinces fight the dairy price downturn.

Mr Little told the Q&A programme some rural areas needed roading and harbour upgrades to boost and diversify local economies.

New Zealand First leader Winston Peters says the milk price downturn shows New Zealand is too reliant on one product, one company and one foreign market.

"This forecast is going to get worse. We've still got people in denial," Mr Peters told the Q&A programme today.

He said the Government was doing "absolutely nothing" to help dairy farmers and the country was too dependent on milk, Fonterra, and China.

Mr Peters told TV One New Zealand should have suspended its participation in the global dairy price auction.

Federated Farmers president William Rolleston said he understood this was not possible, but Mr Peters disputed this.

Dr Rolleston said "of course" there'd be more dairy farmers leaving the business because of the downturn.

"They'll be reducing their costs as much as possible..they'll be cutting down their supplementary feed and cutting their numbers to some extent."

He told Q&A banks understood dairy farming was a "cyclical" business.

"It'll be a crisis if people start panicking..."

Meanwhile, Mr Little said there was still too much secrecy around the contentious proposed Trans-Pacific Partnership (TPP) deal.

He voiced concerns about the possibility the TPP would affect Pharmac, the agency responsible for deciding which medicines get subsidised.

"We support free trade...we are very concerned about something that might undermine Pharmac and its purchasing model."

Mr Little said he was satisfied with how he'd led Labour so far, despite controversy over issues such as leaked real estate data linking "Chinese" buyers to Auckland real estate and a half-hearted debate about whether New Zealand needed a new national anthem.