Polls show Mr Gonzalez far ahead of Mr Maduro.
Many voters said they wanted change after 25 years in power by the Socialist Party PSUV, first under the late President Hugo Chavez and then, after his death from cancer in 2013, under President Nicolás Maduro.
Under their leadership, the PSUV gained control of not only the executive and legislative branches of government, but also large parts of the judiciary.
The last election, held in 2018, was widely considered neither free nor fair, and there were widespread concerns ahead that the vote could be tainted by fraud.
Such fears have been fueled by President Maduro's comments that he will “win no matter what.”
Nevertheless, the opposition took a positive stance going into the election, arguing that if their supporters turned out in large numbers, it would be very difficult for the government to “steal the election”.
Voting in Venezuela is electronic: voters press a button on a voting machine that is assigned to their preferred candidate.
Electronic results are transmitted to the CNE headquarters, but the machines also print paper receipts that are placed in the ballot boxes.
Legally, parties are allowed to send witnesses to verify the number of paper receipts cast at each polling place, but many parties have failed to do so.
The opposition said less than a third of the printed receipts were made public.
Their plan was to check whether these aggregate results were consistent with those published by the CNE.
