Erica Stanford refuses to release file Winston Peters says proves discrimination against Indians

The immigration minister has refused to release the document that NZ First leader Winston Peters claims would show the government "covertly" changing migration settings for Indians.

Erica Stanford says the document is being withheld in full "to maintain the constitutional conventions for the time being which protect the confidentiality of advice tendered by ministers of the Crown and officials".

She says the public value in releasing the document does not outweigh the need to keep it secret.

Peters, also foreign minister, has opposed the deal with India since before it was announced, and had previously criticised immigration provisions he said could mean "open slather immigration" of Indians arriving in New Zealand and taking opportunities "away from New Zealanders".

His deputy Shane Jones has faced criticism for similar rhetoric, warning against a "butter chicken tsunami".

But in June, Peters read aloud from the document in Parliament, claiming it showed Stanford had "approved" changes that would discriminate against Indian citizens. He said the document included officials discussing the importance of not announcing those changes because of the way India would react.

Trade Minister Todd McClay (National) said Peters was wrong, and "should stop promoting misinformation for the sake of gaining votes".

Prime Minister and National Party leader Christopher Luxon also said Peters was "just wrong" about the free trade agreement (FTA), arguing it was "very normal that the minister of immigration imposes bespoke conditions on any FTA visas that are negotiated".

Stanford also said it was "not helpful" for the relationship with India that Peters was making those claims, and that he had broken from usual processes to do so.

But neither NZ First nor National have been willing to release the document to the public.

Peters has claimed releasing the document would be "acting outside Cabinet rules" and urged reporters to get a copy from Stanford.

RNZ first sought a copy on the day Peters revealed the document's existence in Parliament, but Stanford's office initially refused it, referring requests for comment to McClay's office and lodging the request under the Official Information Act.

RNZ pointed out that if the NZ First leader was spreading misinformation as McClay had claimed, the document would clear the situation up, and a prompt response would seem to be in the interests of both National Party ministers as well as the public.

However, in her response provided about 4.30pm on Friday 24 July - the last day to respond to such requests - Stanford said the document - titled 'Implementation of the India-NZ FTA: detailed policy design and timelines' - would not be released.

"I do not consider that the withholding of this information is outweighed by public interest considerations in making the information available," she wrote.

RNZ has complained to the ombudsman.

Stanford's office contacted RNZ to clarify the papers were "still under active consideration" and the contents were still considered "restricted", but once decisions had been made they would be released publicly - although it was possible the briefing paper would not be.