Reacting to yesterday's judgment, Mr Riordan said he intended to appeal the case to the European Court of Justice, although "in order to do so I will first have to go through the Supreme Court of Ireland".
He rejected the judge's finding that if his challenge succeeded it would make government appointments almost impossible.
"There are many, many government positions being advertised, and if you can go through the proper procedures to fill them there is no reason why the same situation couldn't apply in this case."
He said only one person was considered for the EIB post.
There were "no criteria laid down for appointing the individual. There was no procedure for the selection of the individual, and this is where I am saying it is utterly unjust, that people were excluded from the possibility of being nominated purely and simply because they weren't known to the Minister for Finance and they weren't members of the Fianna Fail party."