Venezuela's opposition got a green light on Monday to proceed with efforts to remove President Nicolas Maduro in a referendum, but the crumpling oil giant still appeared far from holding a vote. The National Electoral Council (CNE) said the opposition had collected nearly double the requirement of 200,000 valid signatures on a petition demanding the leftist leader face a recall referendum. But it did not set a date for the next stage in the lengthy process, in which the opposition must collect four million signatures in just three days. And, in a boost to the Maduro camp's claims of rampant fraud, the council's chief, Tibisay Lucena, said the authorities had detected more than 1,000 apparently fraudulent signatures. The opposition blames Maduro for an economic implosion that has seen severe food shortages, hyperinflation, violence and looting erupt in Venezuela, a once-booming country that is home to the world's largest oil reserves. The opposition is racing to force a referendum by Jan. 10, the cutoff date to trigger new elections — four years into the president's six-year term. After that date, a successful recall vote would simply transfer power to Maduro's hand-picked vice-president. A recent poll found 64 percent of Venezuelans would vote to remove Maduro. US Secretary of State John Kerry urged Venezuela not to stall. "The Venezuelan constitution guarantees Venezuelans the right to have their voices heard through the referendum process. And we call on Venezuela's authorities to allow this process to go forward in a timely and a fair manner," he said in Washington. The opposition accuses the electoral authority of being in bed with Maduro. They are hoping pressure from Venezuelans desperate over the collapsing economy will force the government's hand. But the fragmented opposition has struggled to rally mass protests. Many Venezuelans are too busy standing in line for scarce food and basic goods. Fears of violence or a government crack-down also loom. Maduro has declared a state of emergency and given his military sweeping powers over food production and distribution. Venezuela has sunk into crisis as global prices for its main export, oil, have collapsed. Its economy is facing its third year of deep recession this year. Its inflation rate is the highest in the world, forecast to top 700 percent this year. The economic tailspin is threatening 17 years of socialist rule under Maduro and his late predecessor, Hugo Chavez. The opposition won legislative elections in December, only to find its power stymied by the Supreme Court, which it says is also in Maduro's pocket. The high court declared the opposition legislative majority in contempt Monday for ignoring its rulings by swearing in three lawmakers who were suspended over alleged electoral fraud. The opposition accuses the court of using baseless fraud accusations to quash the powerful two-thirds majority it won in legislative elections in December. Time appears to be on Maduro's side. The opposition coalition pushing the referendum, the Democratic Unity Roundtable (MUD), can now formally request the process go ahead — which they must do within two days. The electoral council will have 15 days to respond, then 15 working days to set the dates and locations for the second petition drive. After the second petition is complete, the council will have another 15 business days to count and validate the signatures. Then it is supposed to set a date for a referendum within three months. To win, Maduro's opponents would need more votes than he won the presidency with in 2013 — around 7.5 million. His allies have an arsenal of possible delaying strategies. They have filed more than 8,000 legal challenges against the recall petition and called on the electoral authorities to ban MUD for alleged fraud. In a sign of potential squabbles to come, the electoral council said more than 1,000 fingerprint scans did not correspond with the signatory's identity, more than 400 were repeats and nearly 200 people tried to register more than once. "The electoral authority will ask the state prosecutor's office to investigate the potential usurpation of identity committed by some citizens," Lucena said.