A bill making it easier for businesses with fewer than 20 employees to sack new workers, is likely to pass through Parliament on Friday morning.
MPs spent several hours on Thursday night on a clause by clause debate on the legislation which would introduce a 90 day probation period.
The legislation is being debated in urgency and the Labour Party has accused the Government of ramming it through without consultation.
Labour MP Trevor Mallard says the legislation takes away the "fundamental rights and protection" of every worker.
But Labour Minister Kate Wilkinson, says the bill is carefully drafted and aims to actually help workers into a job.