The Supreme Court is to decide today whether five TDs can join businessman David Hall's challenge to the payment of promissory notes.
They TDs are Clare Daly, Luke Flanagan, Mick Wallace, Joan Collins and Catherine Murphy.
The High Court rejected David Hall's challenge to the Government's issuing and paying promissory notes. It found he had no legal standing to take the case because he is not a TD.
For his Supreme Court appeal against that ruling, the five deputies have come forward arguing it is in the public interest for them to be allowed join his case.
It was submitted the matter is urgent as a payment of €25m is due to EBS in June.
If David Hall wins his appeal, his case will be returned to the High Court for a decision on whether or not the promissory notes are lawful.
However it has also been argued that if the Supreme Court refuses to join the TDs to David Hall's case, they can bring their own challenge.