Sir William Birch, the architect of the sweeping labour law changes in 1991 that removed compulsory unionism, says the change was good for New Zealand.
The National-led Government of the 1990s brought in the most momentous shift in employment law that New Zealand's workforce has experienced.
Five years after the passing of the Employment Contracts Act union membership had halved and multi-employer collective contracts covered only a small minority of workers.
Former PM Jim Bolger oversaw the dramatic undermining of unions, but now says unions have probably become too small.
He says reducing union participation was not a goal of the law change saying unions had a role and a function to play.
Sir William Birch, who was the Minister of Labour when the Employment Contracts Act was introduced in 1991 tells Morning Report he doesn't share the reservations of his former boss, Jim Bolger.