CARACAS - (AP) -- A chamber of Venezuela's Supreme Court dealt a blow Tuesday to opponents of President Hugo Chávez by overruling fellow justices on a petition for recalling him from office.

The court's constitutional chamber struck down a ruling by the electoral chamber, which had ordered election officials to accept 870,000 signatures they had questioned.

Venezuela's opposition wants Chávez recalled and claims to have presented more than three million signatures in December, more than the 2.4 million required to hold a recall vote. But the National Electoral Council said 870,000 of the signatures cannot be deemed valid unless citizens confirm them.

The opposition said that requirement created a logistics nightmare that dooms the recall attempt.

In a widely expected decision, Chief Justice Iván Rincón said the petition did not fall under the electoral chamber's jurisdiction.

The decision might not be final. Chávez opponents can appeal the ruling to all 20 of the court's magistrates, but it was not immediately clear they would do so. The high court is divided into several chambers responsible for different areas of law.

Rincón defended the council's authority to reject signatures. ''The National Electoral Council . . . is an autonomous and independent branch of government,'' he said.

The vote would be the last chance for Venezuela's opposition to oust Chávez at the ballot box before the next scheduled presidential election, in 2006.

Chávez, a leftist firebrand who was elected in 1998 and reelected in 2000, alleges many signatures were duplicated or forged.

The Organization of American States and the U.S.-based Carter Center say they have seen no evidence of widespread fraud.

The two groups have led efforts to bring Venezuela's political crisis to a peaceful resolution after a failed 2002 coup and a crippling strike last year that paralyzed oil production in the world's No. 5 oil exporter.

Opposition leaders accuse Chavez of becoming increasingly authoritarian and dividing this South American nation along class lines.