PALE, Bosnia -- The Bosnian Serbs are poised to reject a last-ditch international peace plan, and warned they would fight to the end against any outside forces sent to punish them for refusing to cooperate.


"If the international community presses us to say yes or no to the offered plan, our deputies and our people will answer no," Bosnian Serb leader Radovan Karadzic said in the northwest Bosnian town of Petrovac.


He was speaking before a crucial session of the Bosnian Serb parliament on Monday expected to reject the plan drawn up by the major powers, dividing Bosnia into two almost equal parts.


The Moslem-Croat parliament also meets on Monday in nearby Sarajevo to consider the same issue, one day before the deadline set by the big powers' contact group for the Bosnian factions to give definite responses.


The plan drawn up by United States, Russia, Britain, France and Germany would give the Moslem-Croat federation 51 percent of Bosnia and the Serbs, who now have 72 percent, the rest.


The Moslem-Croat federation is expected grudgingly to accept the plan and sources close to the Bosnian Serb leadership say the 82-member Serb parliament will wait to hear the decision of their enemies' assembly before issuing their own verdict.


Although the Bosnian Serb parliament is not monolithic, including moderates from the northern Bosnian Bjeljina region and hardliners from the western Banja Luka area, this time they are expected to unanimously reject the plan. "The only question is how they will phrase it. More likely it will be a 'no, but' rather than a 'yes, but'," a Western diplomat said in Belgrade.


The Serbs argue that the proposed map has been drafted solely to suit the Moslem-Croat federation, forcing the Serbs to relinquish as many as 20 towns and carve up Serb territory into three enclaves connected by thin indefensible corridors. "They want to wrest some 20 towns from us as well as major thoroughfares, economic resources, river valleys, but the people are opposed to this and they will probably say no," Karadzic said.


The major powers have warned the Bosnian Serbs that they face more isolation and more war if they reject the proposals.


The UN peacekeeping force in Bosnia might have to withdraw by the end of the summer and make way for a NATO fighting force if the Serbs reject the plan, the UN commander Lieutenant-General Sir Michael Rose said Sunday.


But Karadzic warned he was prepared to call a general mobilization to defend his people.


"America does not want this to end ... and will do anything to make the Serbs go down on their knees. To avoid this the whole nation must be in the army," he said.


His army was prepared to back him fully, he said.


The United Nations fears punitive measure against the Serbs may prompt them to retaliate against the lightly armed peacekeeping troops.