He proposed that multi-ethnic Bosnia-Herzegovina should be split up between Serbia and Croatia - an idea that led to his imprisonment in his native Sarajevo.

After his release, Mr Seselj, a sociologist by training, moved to Belgrade where his extreme form of Serbian nationalism found a more receptive audience in the late 1980s.

As multi-party politics became a reality in 1990, Mr Seselj re-established the Chetniks - the Serbian nationalists' World War II resistance movement - and then became leader of the Serbian Radical Party.

Dream of Greater Serbia

During the Bosnian war Mr Seselj was among those pushing to expand Serbia

But it was in Croatia and Bosnia that Mr Seselj was hoping to realise his dream of creating a Greater Serbia as the former Yugoslav federation began to fall apart in 1991.

His paramilitaries were repeatedly accused of having committed a string of atrocities. At the end of 1992 the US State Department branded him a war criminal and demanded that he should be put on trial.

But so far, the war crimes Tribunal in The Hague has not issued a public indictment against him.

War talk

During the conflicts in Bosnia and Croatia, Mr Seselj fully exploited his capacity to shock and to provoke. He threatened to blow up the nuclear power station at Krsko in Slovenia, near the Croatian border. He warned that Nato air strikes against the Bosnian Serbs would be avenged with missile attacks against targets in Italy, Austria and Croatia.

Meanwhile, as extreme nationalism was on the rise in Serbian politics, at the end of 1992, Seselj's Radicals emerged as the second-largest party after President Slobodan Milosevic's Socialists. The two bitter political enemies then collaborated for a year on ousting moderate politicians, including the federal Yugoslav Prime Minister, Milan Panic.

Rejected Bosnia deal

But that spell of co-operation proved short-lived. Mr Seselj turned against President Milosevic in 1993 when he believed that the Serbian leader was about to agree to a peace deal in Bosnia.

Mr Seselj paid a price for his commitment to aggressive nationalism at a time when President Milosevic was beginning to look for a way out of the war.

Mr Seselj was repeatedly harassed and imprisoned - on one occasion for spitting on the speaker of the Serbian parliament.

Denounced Milosevic

The hostility between the two politicians continued after Mr Milosevic agreed to the Dayton accords which brought peace to Bosnia.

Mr Seselj denounced President Milosevic as the worst traitor in Serbian history, accusing him of presiding over Serbia's greatest defeat since the battle of Kosovo against the Ottoman Turks in 1389.

But President Milosevic and Mr Seselj were brought together once again by a renewed bout of nationalism and self-interest - this time to do with the gathering clouds over Kosovo.

After Mr Seselj nearly managed to beat Mr Milosevic's associates in the presidential race in 1997, he was brought into the Serbian Government. The US State Department responded by saying it would never deal with Mr Seselj, whom US officials branded a "fascist".

Government hard-liner

In the Serbian Government, Mr Seselj, 48, has pursued a hard-line policy, doing his best to muzzle the independent media and, more recently, attempting to exclude foreign journalists from Serbia.

This has even brought him into conflict with more sophisticated Serbian officials, who want to exploit the foreign media for propaganda purposes.

Although Mr Seselj's influence is extensive, it remains, for the time being, limited within bounds laid down by President Milosevic and his Socialist Party associates.