(Adds Maduro, start of security council meeting)
By Andrew Cawthorne and Girish Gupta
CARACAS, March 31 (Reuters) - Venezuela's President Nicolas Maduro promised on Friday to resolve within hours a controversy over the judiciary's annulment of congress which has sparked opposition protests and condemnation from around the world.
The Supreme Court's ruling this week that it was assuming functions of the opposition-led National Assembly was lambasted as a "coup" by critics. They viewed it as a lurch into dictatorship by the Socialist Party that has ruled for the last 18 years.
"I think today we can find a coherent, clear and constitutional solution that clears up doubts and disarms internal and external aggressions," Maduro said at a meeting of the state security council.
Seeking to project himself as above a fray between independent powers and presaging a rumored U-turn by the Supreme Court, Maduro said he had known nothing in advance of its ruling but would address the matter quickly.
Opposition leaders scoffed at that as a hypocritical response to international outrage against his government.
In a rare show of dissent from a senior official, Venezuela's powerful attorney general Luisa Ortega, long an ally of Maduro, rebuked the court earlier on Friday.
"It constitutes a rupture of the constitutional order," the 59-year-old said in a speech on state television. "It's my obligation to express my great concern to the country."
Throughout Friday, pockets of protesters blocked roads, unfurled banners and chanted slogans against Maduro's unpopular government, including "Freedom!" and "No To Dictatorship!"
In volatile western Tachira state, several dozen demonstrators tore up copies of court sentences in front of judicial buildings.
Having already shot down most of the National Assembly's measures since the opposition won control in 2015, the pro-Maduro Supreme Court on Wednesday said it was taking over the legislature's role because it was in "contempt" of the law.
The court went into session on Friday afternoon, further fueling rumors of a row-back to diffuse the controversy.
"The shameless criminals are going to overturn sentences 155 and 156 in the next few hours," said one opposition leader Henry Ramos, referring to this week's two key rulings on the assembly.
"They will have to do the same with the other 52," he added, referring to a raft of previous rulings shooting down congressional measures.
Venezuelan government bond prices fell sharply on the uncertainty.
Maduro, 54, a former bus driver and self-declared "son" of late leftist predecessor Hugo Chavez, was narrowly elected in 2013 amid widespread support for the ruling Socialist Party's oil-fueled welfare programs.
But his ratings have plummeted as Venezuelans struggle with a fourth year of recession, scarcities of food and medicines and the highest inflation in the world.
Critics blame a failing socialist system, whereas the government says its enemies are waging an "economic war". The fall in oil prices since mid-2014 has exacerbated the crisis.
The court's power grab brought condemnations and concern from the United States, Organization of American States (OAS), European Union, United Nations and major Latin American nations.
Ally Russia bucked the trend, urging the world to leave Venezuela alone. "External forces should not add fuel to the fire," it said in a statement.
Maduro accuses Washington of leading a push to topple him as part of a wider offensive against leftists in Latin America.
However, new U.S. President Donald Trump seems to have other priorities or has not yet fully formed a policy on Venezuela.
OAS head Luis Almagro, whom the Venezuelan government views as a pawn of Washington, has been pushing for its suspension from the 34-nation regional bloc, which has announced an extraordinary meeting for Monday to debate Venezuela.
Suspension appears unlikely, diplomats say, given Venezuela's support from other leftist governments and small nations who have benefited from its oil largesse.
"It's all a plan to intervene in Venezuela, provoke national chaos and impose a coup d'etat," Maduro said in a speech. "Venezuela has a powerful democracy ... the constitution is fully intact," he added.
The disparate opposition Democratic Unity coalition, made up of about two dozen parties and groups, declared itself in "permanent session" and promised rolling street protests to demand a new presidential election.
But the coalition is hobbled by disunity: leaders held four overlapping news conferences on Friday.
Opposition supporters are also acutely aware that street tactics have failed on numerous occasions.
Vast rallies in 2002 helped briefly topple Chavez, but he was back about 36 hours later after his supporters poured onto the street and military factions came to his aid.
In 2014, hardline opposition activists led months of protests, but they turned violent and led to 43 deaths, their leader Leopoldo Lopez was jailed, and Maduro consolidated power.
The opposition is hoping the military - whose top ranks still pledge absolute loyalty to Maduro though there is believed to be dissent lower down - may nudge him into bringing forward a presidential election slated for the end of 2018.
But there is no public sign of that happening. (Additional reporting by Liamar Ramos, Diego Ore, Girish Gupta, Eyanir Chinea, Corina Pons, Andreina Aponte, Deisy Buitrago in Caracas; Alexandra Ulmer in Quito; Stephanie Nebehay in Geneva; Kevin O'Flynn in Moscow; Editing by Andrew Hay, Mary Milliken and Kim Coghill)