Here are five key things you should know about the crisis, the worst in decades to grip the South American oil producer.
Government v. parliament
The opposition's clash with Maduro's government became a constitutional crisis in January 2016, when the opposition won control of the National Assembly and put an end to 17 years of control by "chavista" lawmakers loyal to late former president Hugo Chavez and his anointed successor Maduro.
The Supreme Court, seen as close to the government, has systematically blocked parliamentary votes. At the end of March, the court even briefly assumed the powers of the parliament, triggering opposition cries of a "coup" by the state.
By doing so, the court "pulverized the separation of powers" under the constitution, analyst Luis Vicente Leon told AFP.
Among the criticism was a senior voice in Maduro's camp: that of attorney general Luisa Ortega, who decried what she said was "a breaking of the constitutional order." A loyal chavista, she soon became one of the most prominent detractors of the socialist president.
Venezuelan authorities released opposition leader Leopoldo Lopez from a military prison and placed him under house arrest. Source: AAP
Economic collapse
Public anger in Venezuela has swelled apace with the sharp decline of the country's economy, almost entirely dependent on oil exports.
Since 2014, sharply lower oil prices have slashed revenue, meaning fewer imports of needed basic goods, food and medicine, could be bought, leading to shortages. Industry unable to get hold of raw materials have ground to a halt. According to unofficial evaluations, Venezuela's economy shrank 11.3 per cent last year.
Inflation is sky high, estimated to hit 720 per cent this year, the highest in the world.
Maduro has blamed the downturn on an "economic war" waged against his socialist government by a conspiracy of right-wing opponents and the United States.
All-important military
Venezuela's army is a key player in the political crisis. That is reflected by the fact that current or former military officers fill 11 of the government's 32 ministerial posts.
Composed of 165,000 soldiers and 25,000 reservists, the army controls the production and distribution of basic foodstuffs as well as an oil company, a television network, a bank, a auto-assembly plant and a construction group.
Although it has pledged its "unconditional" support to Maduro, it is under strong pressure. Ortega, the attorney general, has criticized it for violence during protests. The opposition has called for it to switch sides.
Analysts reckon the loss of the military's backing would spell the end of Maduro's reign. Recently, a retired general resigned as secretary of the national defence council to show his disagreement with Maduro.
Protesters have been demonstrating for over 100 days. Source: AAP
Appeal to voters
The opposition, hoping to capitalize on its big 2015 legislative electoral victory, had wanted to bring about a referendum asking whether Maduro should be booted from power. But the initiative was blocked at every turn by electoral authorities on the grounds of irregularities.
Now, the opposition is calling for early elections, especially for the post of president. Maduro has rejected that, saying he will stay on until the end of his current term, at the end of 2018.
But Maduro has called on voters to back a new body to rewrite the constitution. The election is due to take place on July 30.
The president says that process will help bring about peace and prosperity.
The opposition, however, sees it as means to bypass the parliament, and it has called for a symbolic vote on Sunday to reject the measure.
Hopes for talk
An effort at dialogue between the government and the opposition, organized under the auspices of the Vatican, was held in October 2016 but failed just one month later.
For one analyst, Benigno Alarcon, that attempt "dearly cost" the opposition, which called off protests and found it difficult to get them going again.
Hopes for a return to talks were raised over the weekend, when the government release a high-profile opposition leader, Leopoldo Lopez, from prison and transferred him to home detention.
For some observers, that raised the prospect that the government wanted to ease tensions and find a way out of the crisis although both sides would have to swallow unpalatable concessions to get there.
