By Petar Komnenic
PODGORICA (Reuters) - A junior partner in Montenegro's governing coalition lodged a court challenge on Thursday against President Filip Vujanovic's bid for re-election, exposing a rift that could threaten the ruling alliance.
The appeal, brought by the Social Democratic Party (SDP) in the Constitutional Court, signals a split that analysts said might deepen if the court rules against Vujanovic, 58, or he is defeated in the April 7 election.
It was a rare sign of discord in the coalition which won re-election in the former Yugoslav republic in October.
The SDP has sided with the opposition in opposing Vujanovic's candidacy, arguing that he has already served the maximum two terms.
Vujanovic's party, the dominant Democratic Party of Socialists (DPS) led by Prime Minister Milo Djukanovic, says he has the right to another five-year term because he has been elected only once since Montenegro broke from its state union with Serbia to become independent in 2006.
The SDP rejects this argument.
"Vujanovic has been president for 10 years already, through two mandates, and according to the constitution he does not have the right to the post a third time," senior SDP lawmaker Borislav Banovic told reporters.
The court is expected to rule within two days, though the opposition accuses the DPS of presiding over a rubber-stamp judicial system.
The mountainous country of 680,000 people began European Union accession talks last year, putting it next in line behind Croatia among the countries carved from socialist Yugoslavia aiming to join the bloc. Croatia joins in July.
Montenegro is under pressure from the EU to crack down on endemic graft and deep-rooted organized crime, which critics say flourished under a cozy elite in charge since the collapse of Yugoslavia in the early 1990s.
Vujanovic's main opposition challenger is Miodrag Lekic, a former diplomat.
Analyst Zlatko Vujovic of the Podgorica-based Centre for Monitoring and Research said the row could yet destabilize the ruling coalition.
"If the court as expected rules in favor of Vujanovic, and the SDP launches a campaign against him in the election, that campaign could result in his defeat and lead to the reassessment and even collapse of the coalition," he told Reuters.
(Writing by Matt Robinson; editing by Andrew Roche)