The Labour Party says the Government's Education Amendment Bill puts children at risk.
The bill passed its first reading in Parliament on Tuesday night, by a vote of 69-52.
Labour education spokesperson Chris Carter says the bill does not require the vetting of parents and volunteers who have unsupervised access to children.
He says statistics show seven children were abused by volunteers over the past couple of years.
But Education Minister, Anne Tolley, says a school can get a police check on anyone if they are unsure.
She says the bill will be considered by a select committee, and anyone with concerns can be heard in that forum.