Justice Minister Simon Power is defending the rolling out of the Public Defence Service and the aim for it to take up to 50% of cases in areas where it is set up.
The service has been criticised by the Criminal Bar Association, which says it will be more expensive and risks having junior lawyers dealing with cases above their ability.
Mr Power told Parliament's law and order select committee that the system - which is established in Auckland, Hamilton and Wellington - is working well.
He said the feedback the ministry has had from the judiciary is that the standard of appearances before them has been high.
Mr Power says the accreditation, competency and oversight regime for the public defender system will ensure the quality of its lawyers is high.
The minister then released the association's media and political strategy, saying it showed criminal lawyers were not engaging constructively with the Government. He said they risked losing their voice at the table.
The association's legal aid spokesman, John Anderson, said Mr Power has demonised criminal lawyers and has not listened to them when they have communicated with him.