However, this arrangement was very short-lived, because early the following day (15 January 2011) the Constitutional Council of Tunisia determined that Ben Ali was not "temporarily unable" to exercise his duties and that the presidency was in fact vacant. The arrangements he had made with the Prime Minister before leaving the country were found to be unconstitutional under article 57 of the constitution. The country's constitutional council, at the time the highest legal authority on constitutional matters, announced the transition saying that Fouad Mebazaa (the Speaker of Parliament) had been appointed acting president.