Senator Ivor Callely has taken his case to clear his name to the High Court.
The Senator is going to the High Court with the aim of securing a legal review of decisions made by the Seanad Committee that suspended him without pay for 20 days.
The committee investigating his expenses found that he misrepresented where he was residing to claim allowances amounting to more than €81,000.
Mr Callely who rejects the finding is also facing an investigation over his mobile phone expenses.
Yesterday, his lawyers made a brief appearance in the High Court to submit a lengthy affidavit to Mr Justice Sean Ryan so that he could read the papers before today's hearing.