Venezuela's opposition steeled itself Tuesday for a new battle in its campaign to remove President Nicolas Maduro in a referendum, vowing nationwide rallies to pressure the crisis-hit government.

Seventeen years after his late mentor Hugo Chavez launched Venezuela on the path of socialist "revolution," Maduro is clinging to the helm of a country in deep crisis.

The once-booming country, home to the world's largest oil reserves, is gripped by severe shortages of food, medicine and basic goods that have triggered violence and looting.

The opposition, which blames Maduro for the mounting chaos, wants to get rid of him with a recall referendum.

It won a key battle Monday when the National Electoral Council (CNE) announced it had collected nearly double the 200,000 signatures required to start the process.

But it appears the war has just begun.

Maduro's camp has vowed to fight tooth and nail. Complicating matters, the opposition says he controls both the electoral council and Supreme Court.

The president's opponents face a long, complicated struggle.

To trigger a recall vote, they must now gather four million signatures in just three days at a time yet to be decided.

Opposition leader Henrique Capriles called two days of nationwide rallies for Wednesday and Thursday to start mobilizing support.

Other opposition leaders camped out early Tuesday at the electoral council's headquarters, awaiting the official certificate declaring they had gathered the necessary signatures to complete the first phase.

After receiving it, they flashed it before television cameras.

They said they would immediately file their formal request for a recall vote. The council has 15 days to respond.

"We're just one step away from the day when our people will exercise their constitutional right and enable us to resolve this crisis," said Juan Carlos Caldera of the Democratic Unity Roundtable (MUD), the broad opposition coalition behind the referendum drive.

The opposition is racing to force a referendum by January 10, four years into the president's six-year term.

Any time after that, a successful recall vote would simply transfer power to Maduro's hand-picked vice-president rather than trigger new elections.

Political analysts say the opposition faces an uphill battle.

"The next step will be as long and hard as the first," said Luis Vicente Leon, head of the polling firm Datanalisis. "The CNE's potential game isn't to avoid a recall referendum, just delay it. And that game's not over."

Maduro took to national TV Monday evening vowing new "victories" and "more socialism" in 2016.

"The right can't get rid of me," he said, calling the recall drive against him a "failed process" marred by alleged fraud.

He also named as the new interior minister a military general indicted on drug-related charges in the United States this week.

Maduro's opponents are hoping pressure from Venezuelans desperate over the collapsing economy will force the government's hand.

But the fragmented opposition has struggled to convene mass protests.

Venezuelans are too busy standing in line for scarce food and basic goods. Many also fear violence or a government crackdown.

Maduro has declared a state of emergency and given his military sweeping powers over food production and distribution.

In a first step toward a referendum, the opposition submitted 1.8 million signatures in May.

Signatories then had to show up at electoral offices to confirm their identity with fingerprint scans, braving long lines and sweltering heat.

Once the second petition drive is complete, the council will have 15 business days to validate the signatures.

If there are enough, it is supposed to organize a referendum within three months.

To win, Maduro's opponents would need more votes than the number with which he won the presidency in 2013 -- around 7.5 million.

A recent poll found 64 percent of Venezuelans would vote to remove Maduro.

However, his allies have an arsenal of possible delaying strategies. They have filed thousands of legal challenges to the recall petition and called for MUD to be banned for alleged fraud.

The electoral council's chief, Tibisay Lucena, said Monday the authorities had detected more than 1,000 apparently fraudulent signatures, saying the cases would be referred to prosecutors.