Shortly after Capriles began speaking to thousands of supporters in a Caracas park, Chavez launched a "chain broadcast" across all public access television in which he celebrated his government's achievements and extolled the virtues of socialism.

"Another radio and television chain broadcast to continue lying to Venezuelans just 20 days before the election," Capriles said via his Twitter account.

Capriles has accused Chavez of using state institutions to tilt the Oct. 7 election in his own favor, from giving supporters cash and apartments, to using state media to glorify his image.