New Zealand's small Jewish community has begun mounting a legal case against the nation's centre-right government in a bid to overturn a ban on the kosher slaughter of meat.

Community spokesperson David Zwartz said that attempts to convince Agriculture Minister David Carter to reverse the ban on shechitah had failed, prompting Jewish leaders to engage a leading Auckland-based law firm.

"Draft proceedings are currently being reviewed by a QC and a final decision will be made following receipt of his advice," Mr Zwartz said.

Mr Carter announced the ban in late May, over-ruling advice from the National Animal Welfare Advisory Committee to exempt shechitah from a new Animal Welfare Slaughter Code.

It means New Zealand's 7,000 Jews have no access to kosher chickens. However, kosher meat can be imported from Australia.

"The minister is firm in his resolve to preserve his position, which does not give the Jewish community a secure, continuous supply of kosher meat," Mr Zwartz added. "This is disappointing and has meant turning to progress the work on a legal action."

The legal case is likely to focus on the ban's apparent violation of New Zealand's Bill of Rights, which protects the right for a person to practise their religion, and its possible breach of the Animal Welfare Act, which contains provisions for religious rights.

The impending legal battle - which some believe could be a test case - threatens to be embarrassing for Prime Minister John Key, whose mother was a Jewish refugee who escaped Austria on the eve of the Holocaust.

The development comes just weeks after the European Parliament voted in favour of new regulations requiring kosher meat to be labelled "meat from slaughter without stunning".