Bulgarians head to the polls on November 21 to elect a president, with incumbent Rumen Radev seen as the front-runner for his stand against corruption.
Radev fell just short of a majority in last weekend's first-round vote, getting 49 percent compared to 23 percent for Anastas Gerdzhikov, the rector of the University of Sofia.
To win in the second round, a candidate needs only a simple majority of votes.
Analysts say that although Radev, 58, is favored to win, there is potential for a surprise after only 40 percent of voters turned out for the first round last weekend held alongside the country's third parliamentary election this year.
'It is crucial that those who supported Radev will not be demotivated to come out again because they expect an easy victory,' Ruzha Smilova, a political scientist at the University of Sofia, told RFE/RL.
Bulgarians voted on November 14 for a new parliament in a bid to break a months-long political deadlock following two inconclusive parliamentary polls in April and July.
In a surprise victory, the new anti-graft party We Continue the Change came in first, followed in close second by the center-right GERB party of former premier Boyko Borisov.
We Continue the Change is now in coalition talks with two other anti-graft factions and the Socialist party, which support Radev.
Gerdzhikov, 58, is backed by the GERB and is likely to get support that party's ally, the Turkish MRF party.
Genoveva Petrova, a managing partner at the consultancy Alpha Research, said the second-round election may be closer than it was last week if supporters of We Continue the Change fail to turn out in large numbers while GERB and MRF mobilize voters on an anti-Radev message.
'Supporters of We Continue the Change may decide that their goal has been achieved. On the other hand, the second round remains an opportunity for GERB to show that it still enjoys wide confidence," she told RFE/RL.
Bulgaria's presidency is largely ceremonial, but Radev has transformed the role and been active in the struggle against corruption in the EU's poorest country.
Radev is a bitter rival of Borisov and supported months of protests against the ex-premier's 10-year rule that began in the summer of 2020.
Borisov ultimately stepped down as prime minister in April due to the mounting anti-corruption protests against him and his GERB party, which accuse Radev of dividing the nation.
But the end of Borisov's rule and months of political deadlock has coincided with the COVID-19 pandemic in the EU member with the lowest vaccination rate as well as rising energy prices.
The second caretaker administration Radev appointed after parties failed yet another attempt to form a government after polls in July was strongly criticized for its poor handling of the outbreak.
Both interim administrations did win public support for revelations about corruption, fraud, and mismanagement under Borisov, giving Radev a boost.
A member of both NATO and the European Union, Bulgaria has been plagued by rampant corruption since overthrowing communism more than three decades ago. It routinely comes in at the bottom of the EU for perceptions of corruption and media freedom.
With reporting by AFP and RFE/RL's Bulgarian Service
Copyright (c) 2018. RFE/RL, Inc. Republished with the permission of Radio Free Europe/Radio Liberty, Washington DC 20036