Mr Culleton described himself as a "senator in exile" as he resisted federal prosecutors' attempts to take over the case in the ACT Magistrates Court.

He alleges Mr Brandis misled the Senate over matters that led to his dismissal.

Mr Culleton's election to the Senate was ruled ineligible by the High Court in February after a drawn-out legal battle that began soon after his election.

His case against Mr Brandis was adjourned in September to give the Commonwealth Director of Prosecutions time to consider whether it would take over the prosecution. Mr Brandis was served a summons but has not faced court over the charge.

Mr Culleton previously said outside court he had "a very strong case" that was in the public interest.

"People now, if their senators aren't going to step up and properly represent their constituents like I am, they can file a private prosecution for $80 in here and go their hardest. I think it's great."

The court heard on Thursday Mr Culleton had since launched a private prosecution in the ACT against former Wesfarmers director Dick Lester, also alleging he perverted the course of justice.

No details in relation to that allegation were aired.

Federal prosecutor Peter Botros said the Commonwealth Director of Prosecutions had taken over both cases.

However, Mr Culleton opposed that move and argued in his submissions the office didn't have the right to step in.

Magistrate Glenn Theakston interrupted Mr Culleton at times, commenting the court was not a "platform to deliver a speech" and "some of the language being used today is a little bit loose".

He heard Mr Culleton's arguments but said they didn't "appear to make a huge amount of sense" and federal prosecutors could take over both cases under law.

Mr Botros said the CDPP declined to prosecute them further and he offered no evidence to support the charges.

"The director now intends to discontinue both matters," he said.

The magistrate dismissed the charges.