Corruption and alleged links with organised crime are the soft under-belly of Balkan governments

Mr Kostunica is undoubtedly more popular and appeals across the political spectrum to nationalists and even ex-supporters of former President Slobodan Milosevic.

Mr Djindjic appears a more pro-Western and also more pragmatic political player.

He is credited with engineering the extradition of Slobodan Milosevic to the UN war crimes tribunal in The Hague, against President Kostunica's wishes, just ahead of a deadline to secure billions of dollars of international aid to his country.

Uncertain future

The rump Yugoslav Federation is still made up of two states - Serbia and the much smaller Montenegro.

Serbia remains a fragile and potentially explosive democracy

With the future of that federation made uncertain by Montenegrin moves towards independence, Mr Kostunica must transfer his power from Yugoslav to Serbian politics in order to survive.

But corruption and alleged links with organised crime are the soft under-belly of Balkan governments.

The sharper the political struggle, the more such allegations are seized on in the wider power struggle, and rival business interests at home and abroad are keen to buy political influence in what they see as the wider economic struggle.

Serbia remains a fragile and potentially explosive democracy.