Julio Borges, a 47-year-old lawyer, took over from former speaker Henry Ramos Allup, whose year in the Democratic Unity Roundtable's top electoral post saw the fractured opposition coalition fail to loosen the socialist president's iron grip on power despite a devastating economic crisis.
"Today, this Assembly opens amid the greatest difficulties," Borges said after being sworn in.
"We are living in unjust and shameful times," he added, calling for "radical change."
Borges, the former legislative majority leader, is a founding member of center-right party Justice First, the largest movement in the Democratic Unity Roundtable (MUD).
The opposition coalition has failed to deliver on its promise to oust Maduro, whose grip on the courts, electoral council and military has stymied all of the MUD's strategies against him: a recall referendum, a legislative onslaught and street protests.
Facing a new year of power struggles, Maduro announced a shake-up of his own yesterday, installing a staunch loyalist, Tareck El Aissami, as vice president.
El Aissami, a 42-year-old of Syrian and Lebanese ancestry, would take over if Maduro were removed from office or resigned.
Hit hard by low prices for its key export, oil, Venezuela is enduring an economic disaster that has led to food shortages and deadly riots.
Maduro blames the crisis on a "capitalist conspiracy" backed by the United States.
His opponents say it was caused by the failure of 18 years of leftist policies under Maduro and Chavez.
Disclaimer: No Business Standard Journalist was involved in creation of this content
