Gabon's Constitutional Court has intervened in a crisis surrounding hospitalised president Ali Bongo, declaring to a storm of criticism that it had modified the constitution to address his "temporary incapacity".Speculation about Bongo's future has swollen since the 59-year-old president was taken to hospital in the Saudi capital Riyadh on October 24. After initially saying that Bongo had been admitted for "severe fatigue," his office on Sunday admitted that he had undergone surgery. It said his condition had "greatly improved" and was "recovering most of his functions" but gave no details about his illness or when he would return.The president of the Constitutional Court, Marie-Madeleine Mborantsuo, late on Wednesday informed reporters that the court had decided to modify the constitution in order to address the scenario of "temporary incapacity" by the head of state.It inserted text in the charter that said: "In the event of the temporary unavailability of the president... certain functions... may be carried out either by the vice president or the prime minister accordingly, on special authorisation of the Constitutional Court."In its first step under this clause, the court authorised Vice President Pierre-Claver Maganga Moussavou to chair a cabinet meeting. Ministers have not gathered since Bongo's absence, meaning that key decisions have been placed on hold.The court had been asked to intervene by Prime Minister Emmanuel Issoze Ngondet.Opposition figures and civil society groups reacted furiously to the court's move, accusing Mborantsuo - a close ally of Bongo and of his father Omar Bongo, who ruled the country for nearly 42 years until his death in 2009 - of illegality. The court "in no respects has the right to modify the constitution," said Paul-Marie Gondjout of the National Union, one of the main opposition parties."She is in effect opening up a new front in Gabon's deep political crisis."* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. The constitution, before its modification by the court, stipulated that only the president had the right to authorise the vice president to organise a cabinet meeting.It also says that if there is a definitive vacation of power - a situation that has to be confirmed by the Court - the speaker of the Senate is named interim president pending the holding of presidential elections within 60 days."This lady (Mborantsuo) cannot be allowed to trample on our constitution and give away the sovereignty of the Gabonese people," opposition senator Jean-Christophe Owono Nguema, told AFP. "I fear the worst for our country."In contrast, Telesphore Ondo, a constitutional specialist, said the court did have a "power of interpretation (and) regulation of the institutions" and was acting legally in amending the constitution at a time of "turbulence."