A change to legal aid payments takes effect on Monday, with the introduction of fixed fees for criminal defence lawyers.
Instead of an hourly fee, a legal aid lawyer will now earn between $300 - $390 for a guilty plea case and up to $580 for a defended hearing.
The changes are the latest fallout from a 2009 review of legal aid, which was highly critical and found evidence of lawyers rorting the system.
The Law Society says there's evidence of lawyers already deserting criminal legal aid work and fixed fees may push more into quitting because payments are up to 30% lower than before.
The High Court will on Tuesday consider a request by the Criminal Bar Association for an interim injunction, to stop fixed fees being imposed.