The ACT Magistrates Court on Friday heard Slipper, pictured, had been in a mental health facility receiving treatment since January.

His lawyer, Trent Jones, said, via telephone link, that his client had been in and out of institutions on account of his mental health for an unspecified period.

Mr Jones told Chief Magistrate Lorraine Walker the defence may apply to have the criminal proceedings dismissed if an appeal to block the case in the ACT Supreme Court failed.

''[But] nothing is set in stone at this stage,'' Mr Jones said.

Slipper, who did not attend Friday's mention, has pleaded not guilty to three charges he dishonestly used about $1000 worth of Cabcharge vouchers to take a taxpayer-funded tour of Canberra wineries in 2010.

But the current criminal matters are on hold while the former federal member for the Queensland seat of Fisher awaits the outcome of a challenge to have the charges stayed.

A Supreme Court judge last month reserved his decision on Slipper's application to end the prosecution against him.

Lawyers for Slipper argued the Parliament, not the courts, was the correct forum to investigate allegations their client had defrauded the Commonwealth.

The defence has asked Justice John Burns to permanently stay the charges because the case would violate parliamentary privilege and was an abuse of process.

But prosecutors say that privilege did not always protect politicians from criminal prosecution.

Ms Walker retained six days for hearing the criminal case in July and relisted the matter for mention in May. Slipper is also the subject to claims of sexual harassment after his former aide, James Ashby, won the right to pursue his claim in the Federal Court.