SARAJEVO, Bosnia-Herzegovina (AP) — Bosnians will vote Sunday in local elections marked by a battle over who will run the municipalities in the part of the country run by Bosnian Serbs — a pro-European Union coalition or the already ruling separatist party with close ties to Russia.

Municipal councils and mayors will be chosen throughout the country, but the main contest will take place in Republika Srpska region between the party of regional President Milorad Dodik — the Alliance of Independent Social-Democrats — and a coalition called The Alliance for Changes.

Dodik advocates secession from Bosnia and has promised Bosnian Serbs a 2018 referendum on independence — something many of them have been seeking since Yugoslavia collapsed during the 1990s. The equally nationalistic coalition sees the future Republika Srpska as a semi-autonomous region within a Bosnia that is an EU member.

The coalition led by the Serb Democratic Party focused its pre-election campaign on bread and butter issues, but also published details of Dodik’s alleged corruption and accused him of throwing the region into poverty during his decade in power.

However, Dodik managed to shift voter’s attention away from the accusations by holding, a week before the regional elections, a divisive Bosnian Serb referendum over a disputed Republika Srpska holiday that the country’s constitutional court had banned because it discriminates against non-Serbs.

The court also banned the referendum, but Dodik conducted it anyway and portrayed the court’s actions as an attack on Serb autonomy. Voters overwhelmingly approved the holiday, although non-Serbs mostly boycotted the vote.

The opposition says the “unnecessary” referendum cost taxpayers 750,000 euros ($840,000) and was used as a ploy by Dodik to divert attention from serious issues facing the region.

Each of Bosnia’s two regions — Republika Srpska and the Bosniak-Croat Federation — has its own government, president and parliament, but the two are linked by a shared state-level government, parliament and a three-member presidency comprised of a Muslim Bosniak, Christian Orthodox Serb and Roman Catholic Croat.

In general elections two years ago, Dodik’s party lost the Serb posts in the state elections to the opposition coalition, but retained power in the regional parliament and government. Since his opponents joined the central government, Bosnia made progress toward obtaining EU membership and begun major socio-economic reforms. Dodik has called them Serb traitors.

A poor showing for Dodik’s party in Sunday’s municipal elections, following the loss at the national level, would be a sign of his diminished popularity among Bosnian Serbs after more than a decade in which he has gone unchallenged.