The Government is being accused of passing the buck on concerns about "factory farming" of dairy cows to an advisory committee.
But the Government says the Green Party is being irresponsible by suggesting it should step in to prevent large-scale cubicle barn farms going ahead.
Prime Minister John Key hassaid the Government does not support indoor farming such as that proposed for up to 18,000 cows in the South Island's Mackenzie Country.
The Greens say such farming practices will wreck New Zealand's international image. But those behind the proposals say the "factory farming" title is wrong, as the animals would be free to move about.
Under questioning in Parliament, Mr Key referred to the National Animal Welfare Advisory Committee (Nawac) having developed a new welfare code for dairy cattle.
This draft code is currently being considered by Agriculture Minister David Carter, who has sought more advice from his officials about whether the code deals with the issue of indoor farming adequately.
Green Party MP Sue Kedgley said the tactic of relying on a welfare code to prevent factory farming would not work, and Mr Key was passing the buck.
"He will have to take leadership himself, and confront the issue, and perhaps use the Government's call-in power to stop this application, if he is serious about stopping it."
Mr Carter said the Greens were running the same old argument when the law was clear about animal welfare issues.
"A minister doesn't suddenly respond to an incident like the last few days by writing a code and promulgating it. And it is irresponsible of the Green Party and Sue Kedgley to continue to call for that sort of response."
Nawac chairman John Hellstrom said he was uncomfortable with the farming methods proposed, but he had advised Mr Carter it would be a poor choice to try to revise the draft welfare code currently on the table.
This would delay having the code in place by up to a year, when there were already "quite substantial" safeguards.
Public submissions on the proposals close on December 18.
