NZ First, as its name suggests, gives "high priority to maintaining and building the manufacturing sector" and wants "a government procurement policy that gives preference for New Zealand firms".

Mr Peters himself isn't so hot on the Middle Kingdom, in 2014 telling supporters "two Wongs don't make a right".

It might fly in the face of importing Chinese-made T-shirts, but Mr Peters says he's just the pilot - and knows nothing about it.

"I haven't got a NZ First T-shirt. You say that - I don't know anything about that," he told The AM Show on Monday.

"I'm at the front of the aeroplane trying to drive it - I'm not at the back sorting out what goes on the toilets and cleaning up the kitchens, right? If somebody's selling a product, I've got no idea what the product is."

The Green Party was quick to point out its T-shirts are made in New Zealand. Wairarapa candidate John Hart tweeted an image of the party's 'Great Greens' shirts, with a "New Zealand Made" tag.