Former Liberian president Charles Taylor is expected to address the international court that found him guilty of war crimes in Sierra Leone.
It is his last chance to speak at the tribunal in The Hague before being sentenced later this month.
The prosecution will press its case for an 80-year prison term, which the defence has dismissed as excessive.
Taylor was convicted of arming rebels in Sierra Leone during its civil war and helping to plan atrocities.
In its landmark ruling last month, the Special Court for Sierra Leone found the 64-year old guilty on 11 counts, including rape and murder.
The BBC's Mark Doyle, in The Hague, says Taylor may tread carefully in what he says on Wednesday so as not to risk angering the judges.
However, the defendant believes many Western and African leaders have conspired against him and our correspondent says those leaders will be watching his speech with trepidation.
From the outset of the trial, Taylor has insisted he is innocent of all charges.
Earlier this month, prosecutors said a sentence of 80 years would reflect the severity of the crimes and the central role that Taylor had in facilitating them.
In a written response, defence lawyers called the prosecution's claim "excessive and not justified".
They said their client should not be made to shoulder the blame alone for what happened in Sierra Leone's war.
During the 1991-2002 Sierra Leone civil war, Taylor - who was president of neighbouring Liberia - supported Revolutionary United Front rebels who killed tens of thousands of people.
The war crimes included murder, rape, the use of child soldiers and the amputation of limbs.
In return, he received "blood diamonds".
Sentence is due to be handed down on 30 May.
Taylor is widely expected to appeal against any prison sentence and the hearing could continue for several more months.
Under a special arrangement with the international court, any prison term Taylor does receives will be served in Britain.