The International Criminal Court will rule on Wednesday whether to uphold the acquittal of Ivory Coast's former president Laurent Gbagbo, the first head of state to stand trial at the tribunal.
Gbagbo, 75, and his former youth leader Charles Ble Goude were cleared of crimes against humanity in 2019 over a wave of post-election violence in the West African nation more than a decade ago.
The prosecution has appealed against the acquittal and wants a retrial over the bloodshed, when more than 3,000 people were killed after Gbagbo disputed the results of the 2010 vote.
Gbagbo refused to hand over power to Alassane Ouattara, the current president, but French troops eventually intervened and Ouattara's loyalists drove Gbagbo from his bunker.
He was sent to the ICC in The Hague the following year.
The judgment will be read out at 3 pm (1300 GMT) by the appeals chamber of the Hague-based court, the ICC said in a statement.
The chamber is led by former ICC president Chile Eboe-Osuji, and includes its current chief Piotr Hofmanski.
Gbagbo has been living in Brussels pending Wednesday's decision but plans to go home if it goes his way, thanks to an olive branch offered by his erstwhile rival.
It was not yet confirmed whether Gbagbo and Ble Goude would be in court for the ruling or attend via videolink because of coronavirus restrictions, an ICC spokesman told AFP.
The verdict will be closely watched in Ivory Coast, where Gbagbo's shadow still hangs over a nation that remains mired in political crisis.
Gbagbo was president from 2000 to 2010, a time of turmoil in the world's top cocoa grower, formerly a haven of peace and prosperity in troubled West Africa.
- 'Tarnished' decision -
His old foe Ouattara ignited fresh unrest last year when he announced he would seek a third term in office -- a scheme that critics said sidestepped constitutional limits.
Clashes claimed 87 lives while most of the opposition snubbed the October ballot -- which Ouattara won by a landslide.
But after Ouattara offered to give Gbagbo passports to aid his return, Gbagbo's Ivorian Popular Front (FPI) party ended a years-long electoral boycott.
The ICC prosecution's case against Gbagbo's acquittal focuses on what it says was a procedural error, when judges in 2019 did not make a proper written judgment but handed down the decision orally.
Prosecution counsel Helen Brady told a hearing this was "no harmless procedural irregularity" but had "tarnished the very essence" of the decision.
The prosecution insisted it had presented key elements of proof with 4,610 documents and 96 witnesses interviewed during the trial.
The judgment is meanwhile key for the credibility of the ICC after a series of high-profile failures and controversies.
Outgoing ICC prosecutor Fatou Bensouda suffered a series of setbacks including the Gbagbo case and the acquittal on appeal of DR Congo former vice president Jean-Pierre Bemba.
Kenyan President Uhuru Kenyatta also saw charges of crimes against humanity over electoral bloodshed dropped by Bensouda.
The ICC is the world's only permanent war crimes tribunal, set up in 2002 to try the world's worst offences.
It has largely focused on African suspects to date, while a probe into the Palestinian territories has enraged Israel and the United States.
Bensouda is also under US sanctions after launching a probe into war crimes by US troops in Afghanistan.
The US signed the treaty forming the ICC in 2000, but has indicated it does not intend to ratify it.