The contest's outcome will likely determine the balance of power in the Balkan nation ahead of a snap parliamentary vote due in June, following months of gridlock after the government collapsed in August.
Montenegrins headed to the polls on Sunday to elect their next president in a vote that could see a young upstart unseat incumbent Milo Djukanovic, who has dominated the country's political scene for decades.
Montenegro's president, elected for a five-year term, has a mostly ceremonial position and most of the political power resides with the prime minister.
Polls open at 7:00 AM (0500 GMT) local time and close at 8:00 PM. Unofficial results are expected late Sunday evening.
The runoff comes two weeks after the first round, where Djukanovic beat back a range of opponents hoping to shake up the political scene, garnering 35 percent of the vote compared to 29 percent for his primary challenger, Jakov Milatovic.
However, analysts have largely favoured Milatovic to win the presidency, arguing the pro-European economist is likely to appeal to a large number of voters desperate for change after decades of rule by Djukanovic and his Democratic Party of Socialists (DPS).
"Milatovic offers a different vision, economic prosperity and cooperation," Dragan Vujacic, a 66-year-old radio and TV presenter, told AFP.
The DPS has been hit by repeated setbacks since the party suffered their first major defeat in the 2020 parliamentary elections.
Since then, Montenegro has stumbled from crisis to crisis that has seen the collapse of two governments.
Djukanovic, backed by former Serbian leader Slobodan Milosevic, arrived at the helm of the former Yugoslav republic in 1991 when he was just 29.
But as Serbia increasingly became an international pariah, Djukanovic pivoted West, broke ties with Belgrade and helped usher in Montenegro's independence in 2006.
Under the leadership of Djukanovic and his party, Montenegro joined NATO, kick-started the negotiating process for EU membership and moved away from Russia's influence.
Upstart versus incumbent
However, his party's rule has been plagued by allegations of widespread corruption and links to organised crime, which Djukanovic denies.
"Here we have a man who has been in power for thirty years, a man who is the personification of a classic dictatorship, a classic abuse of power, the man who has allowed corruption and crime to flourish," Mladen Vukovic, a physician in Podgorica, told AFP.
Ahead of Sunday's vote, Djukanovic has repeatedly questioned whether Milatovic, 36 and his Europe Now party can secure a European future for Montenegro while accusing him of being vulnerable to Serbian influence.
Djukanovic, 61, has also courted ethnic minorities and the Montenegrin diaspora during the final days on the campaign trail.
For years, Djukanovic has sought to bridle the influence of Belgrade and the Serbian church in Montenegro, while carving out a separate Montenegrin national identity.
But it has been no easy task, with roughly a third of Montenegro's population of 620,000 identifying as Serbs.
Milatovic will be hoping to capture the eagerness of young voters looking for an injection of fresh faces into the country's leadership.
Milatovic made political headlines as minister of economic development after the 2020 parliamentary elections, which resulted in the first government not being ruled by the DPS.
The father-of-three made his mark with a controversial economic programme that, among other things, doubled the minimum wage.
Still, the minimum wage is just 450 euros ($490) a month in the tiny country along the Adriatic, which remains heavily reliant on tourism thanks to its picturesque beaches and rugged mountains.
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