The Supreme Court has refused to let 5 TDs join businessman David Hall's appeal as part of his challenge to the government's payment of promissory notes.

The 3-judges ruled there would have to be exceptional circumstances to allow the deputies to become part of the case at this stage.

The TDs are Clare Daly, Luke Flanagan, Mick Wallace, Joan Collins and Catherine Murphy.

They had sought to join the action after the High Court found that David Hall does not have the necessary legal standing to challenge the promissory notes as he is not a Dail deputy.

The Supreme Court will be asked to overturn that ruling in an upcoming hearing.

If David Hall wins, it is envisaged the substantive part of his case, challenging the lawfulness of the promissory notes, will be remitted back to the High Court.

However, it was hoped by Mr Hall's side, that if the court rules against the businessman, the TDs could keep the proceedings alive.

'Case remains urgent'

Barrister John Rogers, SC, submitted the case remains urgent as despite the ECB deal on the Anglo Irish Bank promissory notes, a €25 million payment is due to be made to EBS in June.

The Supreme Court has found there would have to be exceptional circumstances - such as the risk of an injustice - to allow the deputies become part of the appeal.

In a written judgment, Mr. Justice Liam McKechnie said the TDs can institute their own action so it cannot be said 'they will suffer any restriction much less a denial of their access right to justice'.

A fresh challenge has not been ruled out by Independent Luke 'Ming' Flanagan who said the deputies are prepared to exhaust all avenues.