By Daria Sito-Sucic
SARAJEVO (Reuters) - Bosnia's top court upheld a ban on a "discriminatory" national holiday in the country's autonomous Serb Republic, setting the regional government on a collision course with the deeply divided country's central authorities in Sarajevo.
The Constitutional Court ruled that January 9, the date on which Statehood Day is held, discriminated against the region's Muslims Bosniaks and Catholic Croats since it coincides with a Serbian Orthodox Christian holiday.
January 9 is the date when Bosnian Serbs declared independence from Bosnia, precipitating a three-year war that claimed 100,000 lives when rival forces carved ethnically pure statelets out of multi-ethnic Bosnia with the backing of their kin in neighboring Serbia and Croatia.
The court also ordered a halt to next Sunday's regional referendum on holding the holiday. Many see the vote as a dress-rehearsal for a threatened 2018 plebiscite on full secession for the region. The court said the vote harmed the constitutional order.
The Serb Republic said it would push on with the poll in defiance of the court, drawing fire from Western officials who said the referendum was directly challenging the national judiciary and would be considered a threat to the rule of law and stability of the country.
"They cannot halt our decision," said Milorad Dodik, President of the Serb Republic. "We will vote in the referendum. We will show that the citizens of the Serb Republic stand by its holiday."
Bosnian Serbs commemorate Statehood Day by hanging out flags and holding religious ceremonies. But non-Serbs say celebrating it on a religious holiday violates their country's constitutional principle of secularism and pluralism.
Bosnia's international peace envoy Valentin Inzko, who has powers to impose laws or sack officials seen as obstructing the Dayton peace accords that ended the Bosnian war, said disrespect of the court's decisions would "constitute a direct and serious violation" of the U.S.-brokered peace accords.
"The Dayton Peace Agreement is an international peace treaty that cannot be challenged without consequences," the U.S. Embassy in Bosnia said in a statement.
Russia, a traditional ally of Serbs both in Serbia and in Bosnia, has backed it.
(Editing by Thomas Escritt and Dominic Evans)