Attorney-General George Brandis has been plunged into a fresh controversy over his public brawl with the government's top lawyer, after a government MP suggested Senator Brandis restricted access to the Solicitor-General because he "didn't trust" him.

A toxic feud between Solicitor-General Justin Gleeson, SC, and Senator Brandis came to a head on Monday after Mr Gleeson resigned, saying their relationship was "irretrievably broken".

The two men had been at loggerheads over a controversial direction issued by Senator Brandis before the July 2 election which prevented ministers, including the Prime Minister, seeking advice from the Solicitor-General without the Attorney-General's written approval.

In an explosive interview on ABC Radio in Brisbane on Wednesday, Queensland Liberal National MP Andrew Laming said the direction was no longer required "because Mr Gleeson is gone".