Controversial workplace health and safety legislation is now being debated in Parliament.
It was due to have its committee stage debate yesterday, but that was held up by last-minute negotiations with smaller parties wanting substantial changes.
The bill has been heavily criticised for going light on some employers by removing the requirement for small businesses to have elected health and safety representatives.
The committee stage debate is the point at which either government or opposition parties can push for changes to the legislation.
The Labour Party has been lobbying for support for changes relating to exemptions for businesses with fewer than 20 employees and the ability to take private prosecutions over workplace deaths.
New Zealand First leader Winston Peters said his party would put up about eight amendments, including one to ensure there is a workplace representative when there are more than 10 employees.
The Greens will also put up a number of amendments, including one to ensure the new law covers people working at home.
The Maori Party said it had been negotiating directly with Workplace Relations Minister Michael Woodhouse for the changes it wants.
United Future's vote could be the deciding factor for many of the proposed changes but its leader, Peter Dunne, would not confirm where his support lies.
Most farming businesses likely to be exempt
Mr Woodhouse said the majority of farming businesses would not require a health and safety representative under the proposed new legislation.
The minister has released a list of 57 industries which are deemed high-risk and will require a representative, regardless of their company's size.
But he said most farming businesses would not meet the high-risk threshold the government has set for injury and fatality.