A historic verdict on whether the Philippines' top judge should be sacked was due to be handed down on Tuesday in one of the defining moments of President Benigno Aquino's bruising anti-graft crusade. Supreme Court chief justice Renato Corona, on trial in the Senate, is accused of blocking efforts to hold ex-president Gloria Arroyo account for corrupt acts she allegedly committed during her near decade in power. The Harvard-trained lawyer, 63, is also accused of lacking integrity and amassing a secret fortune way above the limits of his salary. He admitted during the trial to having more than $4 million in bank accounts. If Corona is found guilty on any one of the three charges, he could be removed from his post, which would a first for a Philippines chief justice. But senators have also said he could merely be censured, fined or suspended. Aquino has repeatedly said removing Corona is crucial to ending a culture of corruption that pervades all levels of Philippine society and he alleged flourished during Arroyo's term, which ended in 2010. He again warned the public on Tuesday of the consequences of Corona being found not guilty. "We need to closely watch it or face a disaster. But that will not happen with your prayers," Aquino said. Aquino won a landslide election in 2010 after campaigning on a platform to end corruption, and quickly went to work by sacking officials of state companies appointed by Arroyo and a prosecutor seen as sympathetic to her. He claimed Corona last year sought to impede his war on graft by trying to overturn a government order banning Arroyo from leaving the country and escaping prosecution. Arroyo was arrested at Manila airport while trying to leave, and is now in detention while being tried for vote rigging. In December, Aquino's allies in the House of Representatives impeached Corona, sending the complaint to trial in the Senate. Aquino's critics allege that, in his zeal to go after Corona, the president breached constitutional provisions ensuring the separation of powers between the government, the legislature and the judiciary. But various opinion polls have shown widespread support for Aquino. Aquino also enjoys the support of the military, crucial in a country where coup attempts and dictatorship have featured in recent political history. For Corona to be sacked, 16 of the 23 Senators have to find him guilty, and and most have been tight-lipped about how they intend to rule. But in a political system long dogged by corruption and horse-trading, many pundits are also wary that the senators may decide on what is in their own best interests. Trixie Angeles, who heads the Integrated Bar of the Philippines' impeachment monitoring unit, urged the judges to vote based on the evidence presented. "We acknowledge the political nature of an impeachment proceedings, with the senators acting as jurors who will act or vote on behalf of their constituents," Angeles told AFP. "Nobody envies the jurors now, it's going to be a very tough call." Corona claimed innocence when he appeared as the final witness in his defence last week, and insisted his dollar accounts were covered by the country's strict bank secrecy law. His impeachment, he claimed, was a result of a personal vendetta by Aquino following a landmark Supreme Court ruling last year to break up Hacienda Luisita, a giant sugar estate owned by the president's relatives. He signed a waiver authorising the court to scrutinise his wealth, but only if his accusers did the same -- a challenge that was rejected.