Serbia will elect a new president May 6, and the campaign is expected to focus on two key issues: the Balkan country's flagging economy and its bid to join the European Union.
The two leading candidates are Boris Tadic, who formally resigned as president on Thursday to make way for an early election, and Tomislav Nikolic, whose nationalist Serbian Progressive Party has Russia's support.
In March, Tadic persuaded the EU to allow Serbia to officially apply for membership, following the long-awaited arrest of the Bosnian Serb leader Ratko Mladic. He was turned over to a U.N. tribunal in The Hague to face genocide charges.
Tadic also has overseen a more conciliatory stance toward Kosovo, a former province that declared independence from Serbia in 2008. Many countries, including the United States, have recognized Kosovo's independence, but not Serbia or Russia.
Nikolic has won public support for criticizing the widespread social injustice and corruption in Serbia, and for saying Serbia must not join the EU, if that would mean giving up its claim to Kosovo.
He said he is convinced he will win.
"Serbia deserves to be led by honest and better people, and we are much better than those who are now at the helm," Nikolic said.
Parliamentary Speaker Slavica Djukic-Dejanovic, who will formally serve as president until after the election, chose May 6 as the date, the same time that Serbia will hold parliamentary and local elections.
Tadic's presidential term was due to end next year, but he decided on an early vote to boost the chances of his Democratic Party, which has been slipping in recent polls against Nikolic's nationalist Serbian Progressive Party.
Tadic's governing party is being blamed for the country's deep economic and social problems, which are due in part to the global financial crisis.
The nationalists also claim Tadic is willing to sell off Kosovo in a bid for the long and uncertain process of winning EU membership. Tadic has repeatedly denied those claims.
Nikolic is winning the support of disenchanted Serbs by promising jobs and financial security if he is elected. He has claimed to have shifted from being staunchly anti-Western to pro-EU.
Several other candidates will take part in the presidential vote, but they are considered long shots. If no one receives 50 percent of the votes, there will be a runoff.