Labour Party leader David Cunliffe says he has obtained a report showing that the Government has deliberately withheld sensitive information about deep sea oil drilling from the public.
Mr Cunliffe said on Thursday that the report, obtained under the Official Information Act, shows that the risk of an oil spill is seven times greater at a depth of 1.5km than at the 150- to 300-metre depth of oil wells currently operating in New Zealand.
He said the report was prepared for Environment Minister Amy Adams in preparation for Texas-based company Anadarko's plan to drill off the Kaikoura coast.
However, Ms Adams said Mr Cunliffe is incorrect and is misleading the public himself.
She said the report shows there is a 70% probability of an incident such as damage to property, illness or safety issues - not that there is a seven times greater risk of an oil spill.
The minister said David Cunliffe is scaremongering, while Mr Cunliffe in turn is calling for her to resign.