Ramon Muchacho, who governed the opposition bastion of Chacao, has gone into hiding after Venezuela's Supreme Tribunal sentenced him to 15 months in jail.
He has been accused of defying an order to ensure that protests in his district of the capital Caracas did not disrupt transit through the area.
Meanwhile, the country's controversial new Constituent Assembly has passed a decree, giving it more authority than any other national institution, including the judiciary and legislature.
The moves have prompted more countries to criticise Nicolas Maduro's government, saying it has become undemocratic.
Al Jazeera's John Holman reports from Caracas.