Attorney-General Chris Finlayson says as many as 20% of lawyers are failing their clients.
He wants to see judges issue financial penalties to lawyers who waste time or create unnecessary costs.
Mr Finlayson says as many as 400 lawyers currently practicing at the bar, are not representing clients properly and need to lift their game.
He says they don't know how to plead a case, they don't know how to cross examine and there are problems regarding court etiquette.
The Attorney-General says he welcomes moves by the Law Society to introduce competency tests for lawyers.
Judges in England and most states in Australia can issue waste costs orders.
Mr Finlayson says the law needs to be viewed as a service and not as a way to make money.
Criminal Bar Association
But Criminal Bar Association vice president Adriana Pinnock says the Attorney General is overstating the case when he says as many as 20 percent of lawyers are failing their clients.
She says it is not just lawyers who hold up progress in the courtroom.
Ms Pinnock says a police witness may not be available so the case has to be put off, or court staff may lose files and probation is very understaffed.
She says experienced lawyers often leave the criminal sector as legal aid has poor remuneration.