CARACAS, Venezuela (AP) — Venezuelan President Nicolas Maduro is heading toward a showdown with his political foes, promising to seat a new constituent assembly Friday that will rewrite the country’s constitution and hold powers that override all other government branches.

Leaders of the opposition urged Venezuelans to fill the streets of the capital Friday, hoping to provide a strong showing that many people object to the assembly.

The body’s 545 delegates were expected to be installed at the legislative palace in a room just yards (meters) from the chamber where the opposition-controlled National Assembly meets. Maduro, who has said he will use the assembly to punish his opponents, planned to attend the opening session.