The prosecutor of the U.N's Yugoslavia war crimes court demanded Wednesday a 28-year prison term for a Serbian nationalist leader indicted for murder, persecution and torture of non-Serbs during the 1990s Balkan wars.

Vojislav Seselj, a Serbian Radical Party leader, is accused of instigating murder, extermination, persecution, torture and cruel treatment of non-Serbs as part of efforts to create a Greater Serbia during the break-up of the former Yugoslavia at the end of the Cold War.

His crime is grave by scale and heinous by nature, Prosecutor Mathias Marcussen said in his closing argument.

The indictment alleges Seselj was involved in recruitment and financing of Serbian paramilitary units which aimed to expel all non-Serbs form territories in Bosnia, Croatia and Serbia.

Members of those units, many of whom had been Seselj's supporters, murdered, persecuted and deported hundreds of Muslims and Croats from Serb-held areas in Bosnia and Croatia.

He (Seselj) is guilty of all the crimes set out in the indictment, Marcussen said. This crime deserves the punishment that reflects gravity..

Seselj had requested in March, 2011 that he be acquitted on nine counts of war crimes and crimes against humanity, arguing that there was no evidence to convict him. He requested damages for more than eight years in detention.

The International Criminal Tribunal for the former Yugoslavia in The Hague dismissed his request and ordered the trial to continue with the presentation of his defence.

Although still in detention, Seselj has strong political influence on the nationalist electorate in Serbia, attracting votes of so called 'transition victims' who lost their jobs and economic wealth after the country came out of isolation in 2000.

Seselj, who is representing himself at the trial, will present his closing argument next week.

(Reporting By Ivana Sekularac)