Polling stations across the country opened at 7 a.m. local time (0500 UTC) on Sunday, kicking off what was widely expected to be a tightly-fought contest.

The presidential race pits ruling party candidate Tsetska Tsacheva against Rumen Radev of the opposition Socialist Party, who is seen as more sympathetic to Moscow.

Opinion polls in the leadup to the vote put parliamentary speaker Tsacheva, 58, slightly ahead of Radev, 53, but it's unlikely she will secure enough support to claim an overall majority. Instead, the top two candidates are expected to go through to a November 13 runoff, which Radev is predicted to win. 

Analysts say a loss for Tsacheva could prompt the Socialists and other opposition groupings to try to unseat the center-right GERB party's minority government, triggering early parliamentary elections. Such an outcome could lead to months of political instability.

A total of 21 candidates are vying to take over as the country's next president when incumbent Rosen Plevneliev finishes his five-year term in January. The latest polls show Tsacheva finishing on top with around 27 percent of the vote, compared to Radev's 23 percent.

Looking East and West

Both Moscow and Brussels will be watching closely to see whether the new president attempts to tilt the ex-communist country more into the Russian or the Western orbit.

Outgoing President Pleneviev has been outspoken in his criticism of Russia and its president, Vladimir Putin. If elected, Tsacheva is expected to continue Plevneliev's policy. She would also be the country's first-ever female president.

Radev, a former air force commander, campaigned mostly on a pledge to foster cozier ties with Moscow, arguing it was in Bulgaria's interest to build strategic alliances. He has also repeatedly called for the lifting of sanctions imposed on Russia over its role in the eastern Ukraine conflict.

Bulgaria joined NATO in 2004 and the European Union in 2007. At the same time, the small Balkan country shares deep historical and cultural ties with Moscow. It is also heavily reliant on Russian energy. 

Ceremonial role

Relations with Russia, the future of the European Union and the increase in migrants in Bulgaria since neighboring countries closed their borders were dominant issues during the election campaign. Many voters were also concerned about the sluggish pace of poverty and graft reforms under the GERB minority government.

The job of the Bulgarian president is largely ceremonial. While most power in the country rests with the prime minister and parliament, the president leads the armed forces and can veto legislation, sign international treaties and appoint top security and judicial officials.

Some 6.8 million Bulgarians are eligible to vote in Sunday's polls.

nm/jm (Reuters, AFP, AP)