Bosnian Prime Minister Nikola Spiric, an ethnic Serb, resigned on Thursday, saying he could not do his job properly because of meddling by the country's powerful international envoy.

Envoy Miroslav Lajcak took measures this month to break a legislative deadlock between Bosnia's two halves, the Serb Republic and Muslim-Croat federation. The quarrels had long blocked the reforms Bosnia needs to get closer to EU membership.

"I have submitted my resignation to the presidency and expect that the procedure will be conducted in accordance to the law," Spiric told a news conference.

Lajcak reduced the number of ministers needed to be present for the central to government pass laws, preventing any one ethnic group from creating a deadlock by walking out. He called Spiric's move "too emotional" and "completely irresponsible".

The country's three-man inter-ethnic presidency has final say on accepting the resignation. The Muslim president has indicated he would reject it to avoid months of instability. The Serb is likely to accept it, and the Croat has kept silent.

If the presidency adopts Spiric's resignation, his cabinet will not be able to pass major decisions until he is replaced.

Bosnian Serb politicians see Lajcak's change of voting rules as a threat to their autonomy, established by the Dayton accords that ended the 1992-95 war between Bosnia's three ethnic groups.

"Twelve years after the Dayton accords, it's time we lead the country, not be pushed around like cattle," Spiric said.

Bosnian Serbs are openly backed by their ethnic kin in Belgrade, which helped them with money and arms in the war.

Nationalist Serb Prime Minister Vojislav Kostunica said last week they could count on Serbia's full support against the "open threat" to the interests of the Serb people.

"Lajcak is responsible for the crisis in Bosnia," Kostunica told state news agency Tanjug on Thursday. "It would be natural for him to resign, instead of further fuelling the crisis."

RUSSIA FLEXES MUSCLE

Serbia has used hardline rhetoric on Bosnia as leverage in its efforts to stop the Western-backed secession of its province Kosovo, whose ethnic Albanian majority demands independence.

Bosnian Serb leaders have suggested a declaration of independence by Kosovo in coming months could trigger demands in their region to break from Bosnia and join a Serbian homeland.

Linking the future of Kosovo and Bosnia raises the spectre of border changes and forced population shifts in the Balkans, eight years after the West went to war over Kosovo to stop the last ethnic conflict in the break-up of Yugoslavia.

Western ambassadors, responding to an implicit threat by Kostunica to back the Serb Republic's secession if Kosovo wins independence, warned Belgrade this week the two can't be linked.

Serbia, however, appears emboldened by the backing of Russia. In a meeting on Wednesday, the major powers overseeing Bosnia's postwar recovery backed Lajcak fully. But Moscow rapped his timing, warning of "growing tensions in the Balkans".

"(Lajcak's) measures may be counterproductive," Russia's embassy in Sarajevo said, adding that too much intervention by the major powers could make the situation worse.