Denis Riordan, the Limerick college lecturer who this week sought an injunction restraining the Government from nominating Hugh O'Flaherty to the European Investment Bank is no stranger to the higher courts of the land. During the reign of the last Government he took a case arguing that the Taoiseach and Tanaiste should not be out of the country at the same time. Then he challenged the divorce law and last year he was a litigant in a constitutional case seeking a court order preventing the Government amending Articles 2 and 3 of the Constitution following the Belfast Agreement. In 1994 he stood as an Independent candidate for the Euro election in Munster. He has yet to succeed in any of these endeavours.