Slobodan Milosevic has been in talks with his lawyers on the eve of his court appearance at The Hague.
He will be asked to answer charges that he was responsible for murders and expulsions of Kosovo Albanians two years ago.
It is unclear whether the former Yugoslav president would enter a plea or even show up at tomorrow's hearing, which will be the first by an ex-head of state before a UN court.
Milosevic has refused to accept the validity of the court, established by the UN Security Council in 1993 to try offences allegedly committed during Balkan wars.
The US and its allies claim he instigated and supported those conflicts, Europe's bloodiest since World War II.
Meanwhile, in Belgrade, about 15,000 flag-waving supporters of Milosevic's Socialist and allied ultra-nationalist Radical party gathered in front of downtown federal parliament in the biggest protest since the former ruler was extradited last week.
Protesters demanded new elections, hoping they would unseat the pro-democracy government of Serbia, the main Yugoslav republic whose leaders handed Milosevic to the tribunal.
PA