The SPC urged the most senior state officials to be patriotic, saying it was aware of the "pressures and blackmail" they were under.
The SPC said in its letter it was not against the "European unification of peoples and states... or even larger unification processes," but that Serbia was being asked to give up Kosovo and Metohija in exchange for the "uncertain possibility" of getting a conditional date for the start of accession negotiations, the outcome of which it said was unpredictable.
Belgrade has until Tuesday afternoon to decide whether it accepts the solution for Kosovo Serbs being offered by Pristina, with the support of the EU and the US, which envisages giving up executive powers for the police, education and physical planning for a community of Serb municipalities in Kosovo.
Serbia's top officials spent more than five and a half hours yesterday discussing the terms from Brussels and are expected to discuss them over the weekend as well.
"There is no good solution and whatever decision we make, we will regret," Deputy Prime Minister Rasim Ljajic said today.
The Serbian media quoted former US Ambassador William Montgomery as saying that Belgrade had an impossible choice and that whatever Serbia decided, political turmoil was inevitable.
Thousands of people demonstrated in downtown Belgrade against a draft agreement with Pristina which the EU has offered Belgrade, warning state officials that they "will commit high treason if they accept the ultimatum."
Police estimated that about 3,000 demonstrators took part in the rally organised by the Dveri nationalist movement. During the protest, tight police secured several Western embassies. The protest passed without incidents.