The High Court has heard a challenge by TD Joan Collins that a €25m promissory note payment which is due next month could have huge repercussions.
That is because the case aims to test the validity of the recent IBRC Act.
Joan Collins of People Before Profit wants to stop the government paying out €25m on a promissory note for EBS on June 17.
To that end she wants her legal challenge to the payment heard as a matter of priority.
State lawyers have said she should have taken the case sooner but their Barrister Michael McDowell said the case raises very important issues.
The recent IBRC Act permits the Minister for Finance to substitute new securities for promissory notes.
He said Joan Collins wants to challenge the Act and if her case is successful the outcome would have huge repercussions on the Minister's ability to issue these securities and ordinary loan notes.
The case will come back to court next week.