Polling places in Venezuela open Sunday to elect members of the National Assembly in a vote championed by President Nicolas Maduro, but rejected as a fraud by the nation's most influential opposition politicians, AP reported.

Maduro seeks to pack the assembly with members of his United Socialist Party of Venezuela, capturing the last government institution out of his reach. Critics say doing so will smother the last remnants of democracy in Venezuela.

An opposition coalition led by US-backed politician Juan Guaido is boycotting the vote.

The Supreme Court—loyal to Maduro—this year appointed a new elections commission, including three members who have been sanctioned by the US and Canada, without participation of the opposition-led congress, as the law requires. The court also took over three leading opposition parties, appointing new leaders the opposition accuses of conspiring to support Maduro.

Guaido's opposition movement is holding a referendum over several days after the election. It will ask Venezuelans whether they want to end Maduro's rule and hold new presidential elections.

It is unclear whether either side's vote will draw the masses, as neither Maduro nor Guaido are popular among Venezuelans as the nation's economic and political crisis deepens despite its vast oil reserves.

International bodies like the European Union have refused to send observers to Sunday’s election, saying the conditions for a democratic process do not exist.