The Law Society has accused the Government of trying to "look tough on child abuse" while failing to fund frontline services properly.
Proposed changes to child-protection laws would make the public sector more accountable for protecting children and place greater restrictions on known and suspected abusers.
Child Harm Prevention Orders could stop an adult living with children or going to places where children often are, such as parks.
Law Society family law chair Garry Collin said laws are already in place that do what has been proposed and the Government should properly fund social work and related services.
Family law professor Mark Henagan from the University of Otago said there may be an element of "acting tough", but New Zealand does have a poor record of child abuse and some of the proposals are necessary.
Otago University law professor Andrew Geddis said the details of the new laws are still sketchy, with no particulars of what the threshold will be for certain offences.
He said it would be hard to get the balance right, as people who pose no threat and aren't a risk to children could fall victim.
"The cost of protection will be that some people will have these orders put on them when they haven't done anything wrong, and they're not a threat."
