Prime Minister John Key says the Government will support sending to a select committee legislation allowing the use of strike breakers.
The bill in the name of National Party MP Jami-Lee Ross was drawn from the Member's ballot at Parliament on Thursday.
The legislation repeals part of the Employment Relations Act 2000, which prevents the use of volunteers, contractors or other casual employees by an employer during a strike or lockout.
An explanation of the bill says there is an imbalance within the existing law, which provides unions with a significant legislative advantage during negotiations.
Mr Key said he acknowledges that the legislation might be controversial and that opponents will see it as promoting the use of scab labour.
However, he said strikes at the country's ports, for example, have a much wider impact on other industries, so it is not straightforward and there needs to be debate on the issue.
The bill will be introduced to the House for debate on an upcoming Members' day.