President Nicolas Maduro is poised to regain control of Venezuela’s National Assembly on Sunday, in a vote that’s being boycotted by the main opposition parties.

His almost-inevitable landslide will cement his grip on the last major institution in the country that has democratic legitimacy.

A win for Maduro will further weaken the position of opposition leader Juan Guaido. He is recognized as the legitimate ruler of Venezuela by the U.S. and dozens of its allies, but that’s based on his status as head of congress, which he is about to lose.