Forty volunteers will spend much of the long weekend cramped together in a small cage with no entertainment, simulating what it is like to be a caged animal.
'Caged Being: A Social Experiment' is being organised by animal welfare organisation SAFE, and will see the 40 people spend 40 hours in a cage about the size of one-and-a-half boxing rings.
SAFE campaigns director Mandy Carter said each person would have about 1.2 square metres.
"[It's] a really small amount of space, it's just over the size of a phone box.
"They're only going to be allowed to go to the toilet at set times, so they're going to have to get used to not having that freedom to come and go as they choose.
"Like factory-farmed animals, they're going to be fed a very boring grain-fed diet of muesli and soy milk four times a day, so it's going to be a life of deprivation and restriction."
As well as no privacy for nearly two days, there will be no creature comforts or entertainment - no phones, no books, nothing. But a psychologist will be on hand to help any of the 40 should they struggle.
"By default these animals have intense confinement … [factory farms] do not meet the behavioural needs of these animals," SPCA chief scientist Arnja Dale said.
"These are animals directly in our care that we're using for an end purpose so it's responsible and also legislated for that we meet their physical health and behavioural needs, which ultimately means giving these animals a life worth living," she said.
Ministry for Primary Industries director of animal and animal products Paul Dansted said animal welfare legislation was based on "all points of view and the best available scientific evidence".
"We are actively involved in improving the welfare of animals in New Zealand. For example, sow stalls for pigs were banned in 2015 and battery cages for layer hens are being phased out.
"Egg producers have until 2022 to change to a system with better welfare outcomes (such as colony cages or barns)," Mr Dansted said.
Egg Producers Federation executive director Michael Brooks said farmers would abide by whatever the government said was acceptable - but consumers also played a role.
"This is an emotive topic and we understand that, but that's why it's so important that the decisions are made by experts who look at all the studies, and that's what industry follows.
"If there's a range of choices, let consumers make the choice. If consumers go all to free range then farmers would follow them."
SAFE hopes people will vote with their wallets.
"We really want people to realise that the power lies with them. They can be the ones to help animals. We don't have to put up with the terrible way things are," Ms Carter said.
The 40 hours starts at 10pm tonight and the event will be live streamed.
"I didn't even have to think about it, the minute I saw it I thought what a fantastic idea. If it helps raise awareness I was all in," volunteer Danielle Hart said.
One of the youngest volunteers is 17-year-old Ariana Brunet:
"For me it's just 40 hours of my time, but for [the animals] it's their entire life, so yeah I'm prepared to give it up."