The Criminal Bar Association says funding cuts are affecting the operation of the Crown prosecution service.
The association says Crown prosecutors have become under-resourced since funding for the service changed to a bulk funding model.
Association president Tony Bouchier said prosecutors are now more willing to negotiate deals because they no longer have the funding to take matters to trial.
However, Solicitor-General Michael Heron said there are guidelines for making plea arrangements and the key issues are whether there is sufficient evidence and public interest.
Mr Bouchier says jury trials are also being affected by funding cuts, with some being deferred to late next year because of a lack of judicial resources.