Seselj, 53, surrendered voluntarily to the tribunal in February 2003. He is accused of spreading racial hatred and cooperating with former Yugoslav president Slobodan Milosevic to organize Serb paramilitaries into ethnic cleansing combat units in Bosnia, Croatia and Serbia's northern province of Vojvodina.
Hundreds of non-Serbs were subsequently killed by Serb forces Seselj recruited or influenced with his "extreme ethnic rhetoric," prosecutors say.
Despite his current detention, his Serbian Radical Party is the biggest party in Serbia's parliament. Seselj, who faces life imprisonment if convicted, is defending himself at the trial.
"I have no other involvement in the crimes except what I said and wrote," Seselj said yesterday at a final pretrial hearing.
Seselj's trial began a year ago, but was almost immediately halted when the Serb went on hunger strike for 28 days in order to win the right to represent himself. The nationalist leader has accused the European Union, Germany, NATO, the United States and the Vatican of conspiracy against the Serbs, promising to bring proof of this to light at his trial.
In her pre-trial statement, prosecutor Christine Dahl branded Seselj "a shrewd and calculating man, a self-declared scandalmonger," adding that, "Just hearing his fiery threats was enough to make people fear for their lives."
The trial, which is expected to last for around a year, is taking place in the same courtroom where the late Slobodan Milosevic, the former president of Serbia and Yugoslavia was tried. Milosevic died in detention in The Hague in March 2006 before the end of his war crimes trial.
Seselj is to make his opening statement on Thursday.
