A colony cage egg production system being trialled in east Otago is like "an animal concentration camp'', an animal welfare advocate says.
Colony cages are being trialled at Mainland Poultry in Waikouaiti, north of Dunedin, which is New Zealand's largest battery egg producer.
The system is being considered by the National Animal Welfare Advisory Committee, to replace battery cages.
But Save Animals From Exploitation spokesman Hans Kriek today said the system would effectively give each hen only 65 sq cm of space, plus a shared nesting area barely more than an A4 sheet of paper.
He and Green MP Sue Kedgley visited the secretive Waikouaiti trial operation - set up with $390,000 from the Ministry of Agriculture and Forestry - and found it even worse than they expected.
"My impression of this was that it was an animal concentration camp,'' he said.
"The only benefit it can have is it can produce cheap eggs. It has nothing to do with animal welfare.''
Mr Kriek has campaigned against caged egg production for 20 years and can claim much of the credit for battery cages being phased out.
But he implored the Government to get the replacement system right.
In his native Holland, all cage systems will be phased out by next year. Those producers still using them have to look offshore for markets as no Netherlands supermarkets stock cage-produced eggs.
Society for the Prevention of Cruelty to Animals (SPCA) chief executive Robyn Kippenberger said eggs produced by cage systems in the European Union (EU) were stamped as such, so consumers could not ignore the issue.
She claimed the EU was considering phasing out the colony cage system and said New Zealand had an opportunity to get it right first time and be a world leader.
Cages should be outlawed and instead perching or free range systems implemented.
"In the end, a cage is a cage,'' she said. "We can do so much better. We can lead the world instead of dragging behind.''
Green MP Sue Kedgley said the colony cage system consigned hens to a living hell.
"They're like a battery hen cage in drag,'' she said.
"If they're proud of them, then won't they (Mainland Poultry) let us all in and have a look?''
The Green Party pledged to get rid of all cage systems and called on all political parties to join them. Many individual MPs supported them but getting party support was crucial.
A spokeswoman for Agriculture Minister David Carter said he could not comment on the issue as it was the National Animal Welfare Advisory Committee was developing a welfare code, and he could not interfere in the process.
Committee chairman John Hellstrom - who personally eats free range eggs - said it had been considering the issue for about 18 months and had released a draft code earlier this year, which had attracted about 300 substantive submissions.
They all had to be considered and the draft amended to reflect them. He hoped it would be back with the minister in late November - after the general election.
Mr Hellstrom told APNZ colony cages had become the industry standard internationally and it was "absolute nonsense'' the EU was considering phasing them out.
However, he conceded Austria was considering banning them in 2020 and believed Switzerland had banned them. Germany had decided to keep them but with increased cage sizes.
Mr Hellstrom said he believed many New Zealand egg producers would listen to public opinion and opt for barn or free range production but those who favoured colony cages were "probably going to be okay''.
Egg Producers Federation chairman Michael Guthrie, who is also the managing director of Mainland Poultry, said the colony system was a widely accepted and internationally established egg-farming method.
"Colony enclosures provide critical improvements over conventional cages, allowing hens to engage in more natural behaviours,'' he said.
"Colonies allow birds to nest, perch and scratch. They can also stand erect and spread their wings.''