Venezuela's opposition party Union Democratica is calling for a 48-hour general strike in Caracas Wednesday and Thursday, in a continuation of protests over President Nicolas Maduro's plan to elect a new constituent assembly next weekend and rewrite the country's constitution.

Deputy Simon Calzadilla, speaking for Unidad Democratica, urged Venezuelans to go to their electoral centers Monday at 10 a.m. to place banners and protest signs that say "in my voting place there won't be constituent assembly."

Calzadilla, in an emailed statement, also asked citizens to rally to Caracas next Friday to "demand massively" that Maduro's government halt the assembly vote.

"If the regime doesn't cancel this fraud by Friday, the party will inform of the actions it will behold on July 29 and 30," Calzadilla said in the statement. "Center by center, street by street, neighborhood by neighborhood to defeat Maduro's proposal."

Maduro has signaled he would proceed despite U.S. threats of "strong and swift economic actions" and a symbolic vote against it by 7.5 million Venezuelans who participated in an unsanctioned ballot. With the oil-exporting economy already in a tailspin, investors say some sort of ban on crude exports from Venezuela may force the country into default on its debt.