The Labour Party agreed to support the bill after the Government backed its amendments relating to zero hours.
Labour said that without the amendments, the legislation would have entrenched the punitive employment contracts.
Leader Andrew Little said the legislation was an "unprecedented occasion" because labour law changes typically divided the house.
He said the legislation represented "a step forward on many fronts" for workers.
But his party wanted the paid parental leave amendments to go further, by extending leave to 26 weeks.
The legislation extends paid parental leave to casual and seasonal workers and to primary carers who were not biological or formal adoptive parents.
Parents of premature babies would also be eligible for up to 13 weeks of extra leave.
The paid parental leave provisions would come into force on April 1.
Mr Woodhouse said the changes recognised the diversity of modern work and family arrangements.