Corona is accused of trying to protect graft-tainted ex-president Gloria Arroyo from prosecution
A historic impeachment trial of the Philippines' top judge began Monday in one of President Benigno Aquino's boldest yet most divisive moves to tackle pervasive corruption.
Members of the 23-person Senate gathered as judges to determine whether Supreme Court Chief Justice Renato Corona should be removed from his post and become the highest-profile scalp yet in Aquino's anti-graft crusade.
"Renato Corona by his misdeeds is unfit to remain chief justice," lead prosecutor Niel Tupas said in his opening address to the hearing, which could last months and has seen Aquino accused of overstepping constitutional boundaries.
Corona is accused of violating the constitution in his efforts to protect graft-tainted former president Gloria Arroyo from prosecution, while also for allegedly amassing a personal fortune above the limits of his salary.
"The prosecution will show how chief justice Corona became the crowning glory of the cast of accomplices of the former president, and how he protected (her) interest in exchange for the position of prestige and power," Tupas said.
Aquino won a landslide election victory in 2010 on a platform to end corruption which has plagued the Philippines for decades and which he said worsened dramatically during the decade that Arroyo led the country before him.
Arroyo, 64, was arrested in November on charges of rigging the 2007 senatorial vote and is now awaiting trial in a military hospital where she is being treated for what she says is a rare spinal illness.
Aquino then marshalled his allies in Congress to impeach Corona, 63, last month, labelling him a "rogue magistrate" loyal to Arroyo.
Arroyo appointed Corona, her former chief of staff, to the Supreme Court bench in 2002, then to the top judicial post shortly before she stepped down as president.
Public opinion polls show Aquino enjoys overwhelming backing for his anti-graft efforts and the bachelor president is widely regarded as not being corrupt.
However his critics and even some supporters say Aquino has been employing questionable tactics in going after Corona and Arroyo. Some also say that he has dangerously weakened the independence of the judiciary.
Corona, who has repeatedly accused Aquino of trying to move the Philippines towards a dictatorship, made a defiant speech on Monday morning to hundreds of court employees who remain loyal to him.
"I have not wronged the president. I have not wronged the public. I have not stolen anything from anyone," he told the rally at the Supreme Court compound.
In an earlier television interview, Corona said "only death" could remove him from his post.
The Philippines has a turbulent recent history of dictatorship, revolutions and military coup attempts, and Corona's strong words reinforced concerns that the impeachment trial may raise political tensions to a dangerous level.
However, the military has so far stood behind Aquino, the son of democracy heroes who were pivotal in overthrowing 1980s dictator Ferdinand Marcos.
The constitution requires a two-thirds endorsement of the senators, or 16, for Corona to become the first Philippine chief justice ever to be sacked.
So far, only about eight have showed signs they will vote against Corona, and in a political culture where expediency often trumps values, no one in the Philippines can predict with certainty the final outcome.
The varied backgrounds of some of the senator-judges also reflect the colourful side of Philippine politics.
Among them are Marcos' son, the dictator's former defence minister now aged 87, two former failed coup plotters, an ex-police chief once accused of murder, three former action movie stars and a comedian.