The Venezuelan government is alleging that a referendum process calling for the ousting of deeply unpopular President Nicolas Maduro has been tarnished by widespread fraud.
The Venezuela's National Electoral Council (CNE) has ruled that the 1.3 million people who signed the pro-referendum petition need to show up at regional electoral offices to confirm their identity.
Electoral bodies have already invalidated more than 605,000 signatures — almost half due to errors in filling out forms, and about 11,000 because the signatures corresponded to children or dead voters, CNE President Tibisay Lucena said in a news conference.
Adversaries of the ruling Socialist Party say the election authority is seeking to stall the referendum against Maduro, who is facing heavy criticism due to a steep recession, the world's highest inflation, and Soviet-like product shortages.
The elections council next week will allow citizens who wish to withdraw their names from a list of 1.4 million valid signatures to do so, election chief Lucena also said.
The following week, voters who want to leave their names on the list will have to return to have their fingerprints double-checked by election authorities.
This stage of the process involves collecting signatures from 1 percent of the electoral registry.
But the elections council will still have 20 working days to determine if the opposition will move to the next stage of seeking the recall, which consists of collecting signatures from 20 percent of the voter registry.
Opposition leaders have accused the electoral authority of repeatedly changing criteria needed to trigger a recall and adding unnecessary obstacles to slow a referendum that Maduro would likely lose.
Maduro insists the opposition does not actually want a referendum, but rather are seeking a coup.
Two-time presidential candidate Henrique Capriles, the most visible face of the recall campaign, said his signature was arbitrarily rejected along with that of other opposition leaders.
"On what grounds does Ms. Lucena reject my signature?" asked Capriles in response.
If Maduro lost a recall vote this year, fresh elections would be held. But if the vote happens after January 10, Maduro would be replaced by his vice president.
A group of opposition lawmakers on Thursday were attacked as they tried to enter the electoral council headquarters to pressure the elections board to speed up the process. They accused government supporters of staging the attacks.
Majority leader Julio Borges was left bleeding from the nose.