Much hangs on today's judicial review challenging the decision of the Government to appoint former Supreme Court judge Mr Hugh O'Flaherty to the European Investment Bank.
If Mr Denis Riordan succeeds in his challenge, not only will it further delay Mr O'Flaherty's appointment, possibly irrevocably, it will also put a question mark over a raft of Government appointments. If he fails, the Government can breathe a sigh of relief and proceed with the appointment - unless Mr Riordan appeals to the Supreme Court.
Last week Mr Riordan got leave for a judicial review of the decision to appoint Mr O'Flaherty on just one of the three grounds he had argued. This was that the appointment was "unfair, unjust and repugnant to the Constitution" because it was not advertised and he did not have an opportunity to apply. He failed to get leave to challenge the appointment on two other grounds - that Mr O'Flaherty was an unfit person and that Mr McCreevy failed in his duty to the people of Ireland in making the appointment.
Getting leave to have a judicial review - which is an examination of an administrative decision by a High Court judge - is only the first step in having such a decision overturned. This initial hurdle is not a high one, as the applicant only has to demonstrate to the judge that he or she has an arguable case. Often this stage is heard ex parte, that is, without the other side's arguments being put. So a victory at this stage can be hollow, as the case may be lost when the respondent argues against it.
In this case, however, the Government contested Mr Riordan's right to take the case, and lost that argument. However, that does not necessarily mean it will lose the substantive argument, which will be made today.
Because Mr Riordan's arguments have been reduced from three to one, the hearing is likely to be shorter than the initial hearing. It will be made on affidavit, that is written rather than oral evidence. Mr Riordan's affidavit will verify the facts set out in the grounds of his application, while the responding affidavit from the State will reply that the State had the legal right to act as it did.
Therefore it will be a case dominated by lawyers, rather than the main players. Mr O'Flaherty was given the right to be represented at the leave hearing, but his lawyers declined and withdrew.
The court can order cross-examination on the affidavits, but this is only likely if there is a conflict of evidence on the facts. Even if there is cross-examination, which is unlikely, the person cross-examined would be whoever swore the affidavit. In cases involving a Government decision this is usually a civil servant.
Mr Riordan will be taken through his affidavit, and counsel for the Government, Ms Nuala Butler, will reply.
There could be a judgment today, or judgment may be reserved. To an extent, this depends on who will hear the case, which is not certain. Mr Justice Peter Kelly is the judicial review judge, and heard the application for leave, but he might be tied up in another case. There is no requirement that the judge who heard the application for leave must hear the full case. If Mr Justice Kelly hears it, it makes an immediate, or ex tempore, judgment more likely.
However, he, or any other judge, can reserve judgment.
The courts break up for their 10-day "short vacation" tomorrow, so if judgment is reserved beyond tomorrow it might not be given until after June 20th.
The case may not end there. If the Government loses it is very likely to appeal the decision to the Supreme Court, as this would have implications, not only for Mr O'Flaherty, but for a raft of other appointments, from programme managers to members and heads of State boards.
Even if the Government wins the case may not end. Mr Riordan has been to the Supreme Court before with his challenges to Government decisions, and is quite likely to go again.