The Labour Party has cautiously supported workplace reforms - but wants changes to zero-hour contracts before it backs them further.
The party supported the Employment Standards Legislation Bill at its second reading this afternoon.
Labour's workplace relations spokesman Iain Lees-Galloway said if its proposed amendments were adopted by the Government, it would back the legislation through its final stages.
"Today we will vote for this Bill. Next week, we will propose changes ... if the mixture of the changes that are adopted by this House are sufficient to meet our bottom lines, we will support this Bill," Mr Lees-Galloway said.
"If they are not sufficient to meet our bottom lines, I implore the Government's support parties not to cave-in, not to accept something that is watered down ... but to accept our view, and that is this - it is time to eliminate zero-hour contracts from New Zealand."
Labour wants changes to rules which required employees to be on call without a guarantee of work, and to short-notice termination of offers of short-term work.
Mr Lees-Galloway said he suspected the Government had approached Labour because it did not have the numbers to pass the legislation.
Workplace Relations Minister Michael Woodhouse, who previously said minor parties had been misled on the legislation, said the view that the legislation legitimised zero-hour contracts was wrong.
"But I felt that all the hyperbole, the gap between where we were and those views wasn't as large as the drum-beating would suggest."So after discussion with the Council of Trade Unions and others, I am prepared to make minor changes to clauses around availability, and the definition of reasonable notice, to close that gap."The legislation also extends paid parental leave to a broader range of caregivers from April 1.