CARACAS, Venezuela -- Venezuelan leader Hugo Chavez called on Sunday for his supporters to flock to a March in Caracas this week against the opposition, which he said was being financed by exiled ex-president Carlos Andres Perez.

With both the populist president and his opponents planning demonstrations in Caracas on Wednesday to commemorate the birth of modern Venezuelan Democracy on Jan. 23, 1958, Chavez said Perez's link to the opposition was a sign of its desperation.

"The leader of the opposition is called Carlos Andres Perez," Chavez said during his weekly television and radio show "Hello President". "He is moving his tentacles, his ill-gotten funds and applying pressure using his allies here."

Last week, government lawmakers presented to congress a secretly-taped conversation between powerful opposition unionist Carlos Ortega and his former political patron, Perez, who was jailed in 1994 for corruption.

The audio cassette showed Ortega appealing to the two-time president for help in breaking Chavez's control over the National Assembly "by whatever means possible".

Opposition leaders said the tape merely showed two politicians discussing tactics and questioned how the illegal recording fell into government hands.

"Last night I went to the public prosecutor's office to demand an investigation ... to determine who was responsible for this recording of which I fell victim," Ortega told a new conference. "The only conspirator here is Chavez."

The incident came only 10 days after a noisy group of hard-line Chavez supporters besieged opposition newspaper ***El Nacional*** for several hours, sowing alarm among press groups and Human Rights organizations.

"There will be an investigation as to whether a crime was committed or not (with the taping), but that is not the problem," said Chavez. "The problems is we now show that Carlos Andres Perez is the head of the opposition."