"It's difficult to see how this suggestion can be good for children or their parents. It's a breach of natural justice - no final decision should be made without hearing from both sides," Ms Doyle said.
She said parents would be required to go through the educational programme Parenting Through Separation, then family dispute resolution at a cost of nearly $900, and would only then be eligible to make a $220 application to the court to overturn the final order.
She said the changes were aimed at cost-cutting, but would create costs in other courts and agencies.
The society is also concerned about a new track system, in which every application would be considered by a judge and triaged into a fast track, simple track or standard track process.
Under simple track, parents and children would not be allowed a lawyer, and under standard track they would not be allowed a lawyer until a hearing.
Ms Doyle said the change would create a power imbalance and see judges spend more time explaining processes to families in court, work currently done by lawyers.
Family lawyer Louise Elder said Wairarapa families would be hit hard if the changes were made, particularly those with language or literacy barriers and no access to the internet.
"This is a very poor region, it's going to have a heavy impact on people that will no longer qualify for any assistance and want to be able to get advice."
Courts Minister Judith Collins said interim orders would still exist, and no final orders would be made on "without notice" applications.
"Final orders can be made at a hearing with the introduction of a simple process for parties to make changes by consent. This will have the same benefits of 'trialling' an arrangement."
Ms Collins said that rather than create a power imbalance, the changes to legal representation would remove one.
"The court's new role is to focus on the needs of children, rather than on couples with relationship problems.
"We know that going to court is not good for anyone, particularly children, so we want to help parents who can resolve their disputes themselves, to do so outside court."
Ms Collins said the fee for the Family Dispute Resolution could be subsidised for low income earners and was more likely to help parents resolve cases before they get to Family Court.
She said the "track" system would make court easier to navigate, and people would be supported to represent themselves with access to information and forms to help them, such as a standardised affidavit.
Ms Collins said vulnerable people exposed to violence and children needing protection had immediate access to the courts and that would not change under the reforms.
