The Government and its support parties have narrowly defeated a Labour Party Bill that would have imposed mandatory registration for social workers.
At present registration is voluntary and Labour's Carmel Sepuloni, who drafted the member's bill, told parliament that was risky.
"It's dangerous and unacceptable ... there have been several cases of misconduct by unregistered social workers," she said.
"In the 2013 census, 18,000 people identified themselves as social workers yet there are less than 5,000 registered."
National's Alfred Ngaro said he appreciated the intent of the bill but couldn't support it because Social Development Minister Anne Tolley was already looking at the implications of moving to mandatory registration.
"She has commissioned a review and will have a draft report by the end of the year," he said.
The bill was defeated on its first reading by 61 votes to 60.
Labour, the Greens, NZ First and the Maori Party supported it.
National, ACT and United Future opposed it.