The opposition in Venezuela has accused the government of breaking the law by continuing its election campaign on national television.
On the eve of the election, acting President Nicolas Maduro appeared on TV visiting the tomb of Hugo Chavez.
Opposition candidate Henrique Capriles said it was "a shameless violation of electoral rules". On Saturday, he launched an internet channel to broadcast his own campaign.
Venezuelans will vote on Sunday for a successor to Mr Chavez who died of cancer on 5 March.
Mr Maduro is seen as the front-runner, but recent polls said the gap between him and Mr Capriles was narrowing.
The BBC reports both sides staged massive rallies to mark the official end of their campaigns on Thursday.
Since then government ministers have taken to the internet calling for a coordinated wave of tweets celebrating Mr Chavez.
