The Law Society says an expansion to Auckland's Public Defenders Service is being rushed through and has not been properly investigated.
The Government is spending more than $5 million expanding the service out from Manukau and Auckland district courts to the wider region.
The money will be taken from the Legal Services Agency budget.
Law Society spokesperson Gary Gotleib says interested parties were asked to give feedback on the service by the previous government, only to learn that the report was to be abandoned because it was not going to be finished in time for the election.
Mr Gotleib says he does not believe the service is better or more cost-effective than the present legal aid system.
The Government is to spend more than $5 million rolling out the Public Defenders Service across Auckland.
At present, the service operates only at Manukau and Auckland district courts providing in-house legal aid and duty solicitor services. It employs 28 people and handles 2,400 cases a year.
Justice Minister Simon Power says the scheme provides quality service and advice for the public and makes courts more efficient.
Mr Power says he would like to see it become a national initiative eventually.
Mr Power says defendants will continue to have the option of regular legal aid.