The High Court has reserved judgement on Ivor Callely's challenge to his 20-day suspension from the Seanad over his expenses claims.
The suspended Senator is looking to overturn the Seanad Committee's findings that he misrepresented his 'normal place of residence' to claim €80,000 expenses.
Mr Callely's lawyers said he has been wrongly branded as "a thief" and as a "rogue politician milking the system".
They said the Senator filed his expenses claims in accordance with the established rules and the Seanad Committee seems to accept he had done nothing dishonest.
In reply, lawyers for the Committee have argued that its seven members were entitled to make a political and ethical finding against Mr Callely.
They also said that the court does not have the jurisdiction to interfere with that determination.
The three-day hearing has now drawn to a close and Mr Justice Iarfhlaith O'Neill will hand down his judgment at a later date.