Montenegrins voted for a president on Sunday in an election that amounts to a popularity test for the ruling Democratic Party of Socialists, which has held all positions of power for almost two decades.

Polling stations opened at 8 a.m. (0600 GMT) and close at 9 p.m. About 490,000 people in the small Adriatic state are entitled to vote.

Opinion polls show incumbent Filip Vujanovic, an ally of popular Prime Minister Milo Djukanovic, could get the required 50 percent to clinch the largely ceremonial post in the first round, on a platform that stresses experience and continuity.

"We must devote ourselves to a better life, to new values, to a Montenegro within the EU," Vujanovic said in his final rally this week.

The former Yugoslav republic of some 650,000 people voted to end its loose union with neighbour Serbia in 2006, and has since enjoyed strong growth, faster progress towards the European Union and a positive image as a booming tourism destination.

The West says Montenegro's main challenges are weak institutions and endemic corruption, partly blamed on the DPS's continuous rule over a closely knit society that prefers getting things done through personal ties and political patronage.

Nebojsa Medojevic, Vujanovic's main rival in the race, has focused his campaign on these concerns. He accuses the DPS of systematic graft and has sought to win over voters with pledges to fight corruption and review suspicious privatisations.

"We must have an administration which is not stealing from its own state," Medojevic told supporters last week. "We are sending the message that we want changes."

The other challenger, Andrija Mandic, is wooing the votes of Montenegro's 25 percent Serb minority by promising closer ties with Belgrade and Moscow.

"I guarantee Montenegro will never slap itself and Serbia in the face by recognising Kosovo's independence," he said of the former Serbian province, which seceded in February with Western backing over the objections of Serbia and Russia.

A foreign analyst speaking to Reuters on condition of anonymity said Vujanovic's likely win shows Montenegrins prefer to play it safe.

"If the DPS were to lose, a lot of people believe they will lose their jobs," the analyst said. "When people are still poor and living on the edge, these things influence their choices."