While most people will be relaxing on their long weekend, 40 people are spending it cooped up in a cage with just a telephone box of space per person.

It's part of a campaign by animal welfare group SAFE, running for 40 hours in protest of colony cage hen farming.

The egg farming industry claims colony cages actually have a lower rate of mortality than free-range farming.

But SAFE Campaigns Director Mandy Carter believes it's about the quality of living while they're alive.

"Mortality is only one known aspect of animal welfare," she said.

"It's really going off the point because animals in cages are living a horrifying life."

Ms Carter said the point of the protest is to demonstrate the conditions caged chickens live in.

"If we did this to cats and dogs, people would be prosecuted. So why is it okay to do it to farm animals who are just the same as our cats and dogs in how they can suffer?"

The group plans to stay in the cage all weekend, live-streaming their ordeal on social media.

However, the egg industry argues that a protest directed at the practice of keeping chickens in colony cages is misguided.

At the Egg Producers Federation, Michael Brooks said colony cages have been cleared by experts, including vets and SPCA representatives.

"That group of experts took into account all the evidence and said, on balance, [they] see colonies, barn and free-range all offering good welfare - and after that it's a choice for the consumer."

Colony cages are larger than battery cages with room for the birds to perch and scratch.