Both leading presidential candidates criticized the ruling by the National Electoral Court, with the leftist Evo Morales warning the "people could rise up against the court." His rival, Jorge Quiroga, urged Congress to move on the dispute over the allocation of congressional seats, saying Bolivia's fragile democracy was at risk.

Bolivia's caretaker president, Eduardo Rodriguez, has said he will step down in January even if elections are delayed, leaving the nation without a president. The December vote would have allowed Bolivians to elect his replacement, as well as members of the bicameral congress and governors.

Bolivia, the poorest country in South America, has seen two presidents driven out of office by street protests in the past two years. Rodriguez became interim president in June following President Carlos Mesa's resignation.

But court spokesman Salvador Romero told reporters that elections could still be held later in December if Congress can resolve its dispute in the coming days.

The disagreement stems from a Constitutional Court ruling in September that Congress must reallocate its seats before the upcoming election to reflect Bolivia's 2001 census.

Provinces set to gain seats, Santa Cruz and Cochabamba, are demanding the reapportionment be done as the court has ruled, while the provinces set to lose seats want to wait until the 2011 elections.

Rodriguez is analyzing the court's decision and is committed to trying to hold the elections Dec. 4, said presidential spokesman Julio Pemintel.

"We're hoping on Monday that we'll be able to get the various regions together, members of congress and other interested parties to reach some agreement that can guarantee the elections for December," Pemintel said.

Rodriguez has not rejected the idea of issuing a decree that would redistribute the seats and bypass the congress, Pemintel added.

Morales, an Aymara Indian coca farmer who holds a slight lead in the polls, accused the court of conspiring with his political rivals to postpone the elections.

Quiroga, a U.S.-educated industrial engineer, called on Rodriguez to reapportion the seats by decree if Congress is unable to reach a decision.

"They need to get airplanes and get the air force to bring the members of congress here to get an agreement," Quiroga said. "Beyond being damaging for the election, this is damaging for the country, for the people."

The postponement comes amid rumors of foreign intervention and coup plots as a monthlong political crisis has deepened. Morales has accused the U.S. and other political enemies of mounting a "dirty war" against him.

Earlier Friday, U.S. Ambassador David Greenlee rejected claims that Washington is planning a coup.

"I don't know where this idea has come from, but the truth is you can see our conduct here, we're with Bolivia, we're with democracy," Greenlee said. "There's no intervention, there are no threats.

Morales has said he would decriminalize coca farming if elected. Coca is used to make cocaine, but it is also has traditional uses among Bolivia's Indians, including chewing the leaf or making medicinal teas. U.S.-backed efforts to eradicate coca plantations in the war on drugs have led to clashes with Andean farmers.

Quiroga wants to keep Bolivia on a free-market track. The Texas A&M alumnus promises to attract foreign investment and to be tough on coca-leaf farmers who sell to the cocaine industry.