Zero-hours contracts involve an employee having to be available for work without an employer setting a minimum number of hours, and no compensation is paid if the employee does not work.
Yesterday's measures, announced by Workplace Relations and Safety Minister Michael Woodhouse, means that where an employer and employee agree to a set number of hours, it must be stated in the employment agreement. Other changes include employers not being able to cancel a shift without reasonable notice or compensation, not limiting an employee's options on secondary employment and not making unreasonable deductions from wages.
Mr Peterson said giving employees "a system where there is no ambiguity" and "clear protection and guarantees" around hours was what was needed.
"[Give] people clearer definitions of what their work is ... clearly spelled out," he said.
Labour Party leader Andrew Little said yesterday that the Government had entrenched unfair employment practices in law.
"Once again National has shown it is on the side of exploitative employers, not employers who use good practice, and certainly not on the side of vulnerable workers."
Mr Woodhouse said unions were now trying to "get rid of casual agreements".
"The unions have long had a view that they don't like casual agreements. We don't think that's realistic. That was never going to be the target on any of the reforms."
Zero-hours contracts would be "unlawful in the future".