Venezuelan authorities have banned top opposition leader Henrique Capriles from running for office for 15 years, the latest move in an increasingly tense power struggle in the crisis-hit country.

Capriles read from excerpts of the comptroller general's order at a rally on Friday night in which he urged supporters to take to the streets, beginning with a previously scheduled demonstration on Saturday, to defend their political rights and demand the removal of President Nicolas Maduro.

"When the dictatorship squeals it's a sign we're advancing," he said in a speech surrounded by other leading opposition figures, many of whom themselves have been targeted. "The only one who is disqualified here is you, Nicolas Maduro."

The 44-year-old Capriles has been the most prominent leader of Venezuela's opposition over the past decade, twice coming close to winning the presidency.

He is currently governor of Miranda state, which surrounds Caracas.

The ban deals a blow to the opposition after stepped-up protests this week and accusations that Maduro is tightening his grip on power and cracking down on dissent.

Leaders in the ruling socialist party have accused Capriles in recent days of trying to provoke a bloodbath through his leadership of protests, many of which have ended in tear gas and rubber bullets.

Violence erupted for a third straight day on Thursday, leaving one demonstrator dead.

IN PICTURES: Hardship and political theatre in Venezuela

The ruling said the sanction was due to "administrative irregularities" by Capriles in his post as governor.

Authorities have been investigating Capriles since the beginning of the year for what they say are a half dozen administrative irregularities, including taking suspicious donations from abroad.

The move effectively bans Capriles from running against Maduro in a general election due next year.

It is part of a broader government crackdown that began with a decision last week by the Supreme Court to gut the opposition-controlled congress of its last vestiges of power.

The decision was later reversed amid widespread international condemnation.

The comptroller's office notification to Capriles said he had 15 working days to appeal the decision at that office or 180 days to ask for its annulment at the Supreme Court. Both are pro-government and unlikely to overturn the decision.

Capriles lost narrowly in the 2013 election that brought Maduro to the presidency after the death of Maduro's mentor Hugo Chavez.

The collapse in prices for Venezuela's crucial oil exports has sapped the country's revenues, prompting shortages of food, medicine and basic goods along with a surge in violent crime.

The opposition blames Maduro for the economic crisis. He says it is due to a capitalist conspiracy.

The wave of protests has revived fears of broader unrest in Venezuela, where 43 people were killed during riots in 2014.

The country has undergone three attempted military coups since 1992.