Guaido, a close ally of political prisoner Leopoldo Lopez, has also spoken with a lawmaker son of Brazilian President Jair Bolsonaro. In an opinion piece in the Washington Post, Guaido laid out his argument for why the assembly - the only democratically elected body left - should form a transition government and call for new elections.
"As president of the National Assembly, I am fully able and willing to assume the office of the presidency on an interim basis to call for free and fair elections," Guaido wrote. "With a united National Assembly, along with the military, the people and even those who still support this regime, we can materialise the mandate the Constitution endows on us."
The Opposition and at least 60 countries have argued that Maduro's election victory was won through fraud and that his second term, which on began January 10, is illegitimate. Since Maduro succeeded Hugo Chavez in 2013, the country's economy has collapsed and it has been ravaged by hyperinflation and hunger.
Trained as an engineer, Guaido began organising demonstrations against Chavez more than a decade ago. He formed a close relationship with Lopez, then a Caracas mayor, and later helped him form the Popular Will party. Even with Lopez under house arrest, they talk several times a day.
Guaido "is smart in realising he can't just declare himself president," said Jennifer McCoy, a political scientist at Georgia State University and former director of the Americas Programme at the Carter Centre.
"There's also risks. It strikes a clear fight with the Government and gives them an excuse to disregard international figures and find some reason to arrest him, as they've done to others."
The Maduro regime is taking the threat seriously. On Monday, political police briefly detained Guaido. Though officials later disavowed the action, video of the arrest spread quickly. In a Tuesday speech, Maduro scoffed at the idea of handing Guaido the reins of power. "I'm going to give you the sash, big boy, to see what you do with the country," Maduro said, referring to the president's tricolour ceremonial garment.
Both the opposition and government have called for large marches on January 23 as a test of strength and faith from their followers.
"The perception now is there is a more systematic and coherent plan than in previous years," Diego Moya-Ocampos, a political risk analyst at IHS Markit, said referring to the legislation passed yesterday. "In reality, they're still sort of making it up as they go along, but the Opposition is at least united in their goal to secure elections."
Moya-Ocampos said he doesn't necessarily see Guaido becoming an interim president, and instead believes that he's ultimately "trying to force an election. He's a means to an end".
- Bloomberg