Australia's first law officer has delivered a sharp rebuke to Immigration Minister Peter Dutton, and reminded government ministers of the need to respect the rule of law and authority of the courts.

In a Sunday night speech to the International Bar Association in Sydney that initially flew under-the-radar, Attorney-General George Brandis delivered a full-throated defence of the rule of law and the legal profession.

While he did not name Mr Dutton, Senator Brandis' comments have been interpreted as a repudiation of his cabinet colleague, who in August agreed with 2GB shock jock Alan Jones that lawyers representing asylum seekers were "un-Australian", and expressed frustration with lawyers acting on behalf of people in detention.

In his speech, Senator Brandis pointedly declared to 4000 delegates that "we, as lawyers, must always be alert to ensure that due process is always observed, that the right of access to the courts is never denied [and that] that the role of lawyers in representing their clients is always respected".