The Labour Party is accusing the Workplace Safety Minister of deliberately changing risk data to exclude agriculture, one of the country's most dangerous industries, from new health and safety rules.
Under the controversial Health and Safety at Work Act, which takes effect on 4 April 2016, any workplace that falls into the high-risk category will be required to have a health and safety officer.
Labour's spokesperson for labour issues, Iain Lees-Galloway, said agriculture was initially classified as high-risk. He said Workplace Safety Minister Michael Woodhouse changed the data settings so agriculture and dairy farming came in as low-risk.
Mr Lees-Galloway said Mr Woodhouse would now be known as the minister who failed to protect workers in one of the most dangerous industries.
Officials had repeatedly warned Mr Woodhouse that the data he was using could be highly misleading, he said.
"The minister was advised repeatedly that agriculture is a high-risk industry, that it has a significant rate of injury and death, and by any reasonable measure, it should have been classified at high-risk."
Under the settings the minister chose, worm farming and mini golf were classified as high-risk activities.
Mr Woodhouse has declined interviews this afternoon.