Closing presentations in the Beverly Cooper-Flynn libel trial are due to be completed later today.
The Mayo TD claims she was libelled by RTE in June 1998 when the State broadcaster reported that she encouraged people to break the law by investing in off-shore accounts.
She is also suing retired farmer James Howard, who made the allegations to RTE.
Ms Cooper-Flynn, who worked with NIB at the time, denied the claims and said the person who dealt with the clients was a woman called Ms Patricia Roche.
Judge Frederick Morris is expected to direct the jury later today and the loser is expected to face a legal bill of over £1m.
If the judgement goes against Ms Cooper-Flynn, her career in politics could be over, as Dail rules state that a TD cannot hold a seat in the Oireachtas if bankrupt.