Maduro was tapped by Hugo Chavez as his preferred successor to the presidency, and is quick to invoke the late leader's name, but orthodox socialists are grumbling over liberalized currency reforms they say are counter to the revolution.

The tensions came to a head last week when Maduro fired Planning Minister Jorge Giordani, a Marxist economist whose Spartan lifestyle and anti-capitalist doctrine earned him the nickname "the Monk." Giordani is not going into forced retirement quietly.

In a lengthy tract published on several websites, he has accused Maduro of undoing Chavez's gains and failing to control his administration, implying corruption and incompetence. It is, he said, "painful and alarming to see a Presidency that does not convey leadership."