The Law Society is calling on Parliament to defer legislation overhauling the legal aid system.
President Jonathan Temm says it should wait until the outcome of a review of the Family Court.
He told Parliament's Justice and Electoral Select Committee that it must be cautious in making changes to how legal aid is funded.
The committee is hearing submissions on the Legal Assistance (Sustainability) Amendment Bill.
Mr Temm said the bill covers the same ground as a review of the Family Court, the findings of which are expected to be reported to the Government in March.
The committee also heard the proposed law would create a two-tier justice system.
A Criminal Bar Association spokesperson Helen Cull said fixed legal aid fees would create an imbalance between the resources of the Crown and the resources of the defence.
She told the committee that legal aid needs to remain available to those that need it to ensure they get a fair trial.