Venezuela's president, Nicolas Maduro, says the country's main opposition parties are banned from taking part in next year's presidential election. He said only parties which took part in yesterday's mayoral polls would be able to contest the presidency. <br/><br/>Leaders from the Justice First, Popular Will and Democratic Action parties boycotted the vote and said the electoral system is biased. In October, the three main opposition parties announced they would be boycotting yesterday's vote to elect mayors in more than 300 towns and cities.They said the vote served what they called President Maduro's dictatorship. <br/><br/>President Maduro insists the Venezuelan system is entirely trustworthy. In a speech, he said the opposition parties had disappeared from the political map. He said a party that had not participated in yesterday's vote and called for the boycott of the elections can not participate anymore.