Andrew MacDowall in Belgrade -

Despite an increasingly acrimonious campaign, Serbia looks set to continue its move towards the European mainstream after the presidential run-off on Sunday, May 20.

The bitterly-contested second round of the presidential election pits incumbent Boris Tadic, who is seen as western-leaning and has overseen the country's progress towards EU membership status, against Tomislav "Toma" Nikolic, formerly a fire-breathing nationalist but now supposedly a moderate. That both candidates have espoused EU accession is a sign of the changes that have taken place in Serbia since the ouster of strongman Slobodan Milosevic in 2000.

Tadic is widely expected to win; even Nikolic's confidantes are said to be sceptical of his chances. But a strong showing for Nikolic would highlight once again that a substantial proportion of Serbia's population is uncomfortable with the direction the country has been taking.

Indeed, all but a landslide for Tadic would be a grudging acceptance of the incumbent as the better man for the job. While Serbia won official EU candidate status in March, the country's economy is sluggish and lacks clear long-term direction, and the populace is disillusioned with a political elite seen as corrupt and remote. Then there is the issue of Kosovo, the region which declared independence in 2008, which both Tadic and Nikolic claim they see as an inalienable part of Serbia.

Gorgeous George

In the first round of the election, Tadic won 25.31% of the vote and Nikolic 25.05%. Candidates from other parties took the remainder, and it is the votes of their supporters which will determine Sunday's contest. And Nikolic's Progressive Party narrowly won a parliamentary poll held concurrently with the first round of the presidential election, and has 73 seats in the 250-member parliament to the 67 held by Tadic's Democratic Party. But it seems likely that the Democratic Party will team up with its allies from the last parliament, most notably the Socialists, to form a workable majority. Constitutionally, the prime minister has more power than the president, but Tadic has effectively taken control of the government in his eight years as president, and is very much the leader of his coalition.

Tadic, once allegedly dubbed the "George Clooney of the Balkans" by Silvio Berlusconi, cuts an urbane figure, and is an energetic and telegenic campaigner. He has successfully steered a course towards the EU while maintaining Belgrade's opposition to Kosovo's independence. Many see this as a contradictory stance, given that it is unlikely that Serbia can join the EU without conceding on Kosovo's sovereignty. Tadic and his allies are widely seen as having privately given up on Kosovo while saying otherwise to the Serbian public, an impression that probably has some basis.

A Tadic victory would mean more of the same for Serbia; the commencement of accession negotiations with the EU, a very gradual move towards conciliation with the Albanian-dominated Kosovan government in Pristina, and a broadly pro-investment economic strategy.

In contrast to the smooth Tadic, Nikolic is seen as somewhat uninspiring, and has little talent for public speaking. But he has attempted to portray himself as a man from outside the political elite.

Nikolic was defeated by Tadic at the last presidential election, in 2008, when the former was standing as the candidate of the ultranationalist Serbian Radical Party, espousing a rejection of the EU, no compromise on Kosovo, and a turn towards Russia. Just four years later, having left the Radicals and founded the Progressive Party, Nikolic is standing as a moderate conservative, supporting EU accession albeit with a harder line on Kosovo. Nikolic's volte-face, and the poor showing of the formerly powerful Radicals in the recent parliamentary poll, is indicative of the shift of Serbian politics towards a pro-European centre ground.

In policy terms, then, there is not a huge gulf between the two men and their parties, unlike 2008, when Serbia faced a clear choice between ultra-nationalism and pro-western liberalism. Nikolic's main advantage is that he is opposing the ruling coalition and Tadic, and thus can gain support from those looking to punish the government for Serbia's economic difficulties and widespread corruption.

Despite his change of heart on the EU, Nikolic is also likely to gain some support from those who disavow accession. This week he made a pact with the (confusingly named) Democratic Party of Serbia, which opposes EU membership, in a clear bid for euro-sceptic votes. But the agreement merely states that the parties will work towards having a referendum on the EU. Not only is this a vague proposal, but such a referendum would be likely to support accession.

While Serbia's sloughing off of its troubled past continues, whoever wins faces serious challenges. Much of the population continues to scrape by on low wages, which average only around €400 per month. The Kosovo issue remains unresolved, and the process of EU accession will be long and difficult - membership is not expected before 2020, and will involve much judicial, administrative and economic reform.