Ex-Bosnian Serb army chief Ratko Mladic is boycotting a UN war crimes court where he is due Monday to plead on charges over his role in the 1992-95 Bosnian war, including genocide, a lawyer said.

‘Mladic has told the prison authorities that he does not want to appear in the courtroom (Monday) and will not enter a plea,’ Milos Saljic said by telephone.

‘He decided not to reappear as his defence team has not yet been approved,’ Saljic said.

Mr Mladic, arrested in Serbia and delivered last month to the Hague-based UN war crimes court for former Yugoslavia (ICTY) after almost 16 years on the run, is supposed to be back to the courtroom tomorrow to plead to charges of genocide, crimes against humanity and war crimes.

Mr Mladic was first hauled before the ICTY on 3 June, where he chose not to plead to what he called 11 ‘obnoxious’ charges.

The court's regulations then gave him a month before a second appearance where Dutch Judge Alphons Orie will again put the question to him.

‘Mladic said he could not study the indictment and therefore prepare a plea without his lawers,’ Mr Saljic said, adding he was one of the attorneys picked up by the defendant.

Another member of the team will be a Russian lawyer, Mr Saljic said, adding that the defence team has yet to be approved by the ICTY.

However Nerma Jelacic, the ICTY's spokeswoman, denied any knowledge about Mr Mladic's plan.

‘The Tribunal has not been officially notified of such an intention, so the preparations here are going in accordance with the scheduling order for his appearance tomorrow at 10am,’ Ms Jelacic said later.

But Saljic said that the only way Mr Mladic could be brought to the courtroom was ‘by force’.

Like his wartime political chief Radovan Karadzic, who has been standing trial in The Hague since October 2009, Mr Mladic faces genocide charges for masterminding the Srebrenica massacre - Europe's worst mass killing since World War II - when his forces killed some 8,000 Muslim men and boys in several days of July 1995.

The charges for genocide, crimes against humanity and war crimes also include the 44-month siege of the capital Sarajevo from May 1992 in which 10,000 people died.

Both Mr Mladic and Mr Karadzic face a maximum sentence of life in prison.