The article is a little thin. 
Selected portions from the Guardian that may say more: 

"Maduro has said the assembly will help bring peace to the sharply divided country where, despite its oil wealth, many Venezuelans are going hungry because of food shortages and spiralling inflation. But the opposition said it is little more than a power grab to consolidate the ruling socialist party’s grip. It is boycotting the assembly and demanding general elections instead." 

"A government ban on public demonstrations in the run-up to the election reduced turnouts for nationwide protests called by the opposition"

"But polls show that 70% of Venezuelans do not want a constituent assembly, although turnout on Sunday may not reflect that. To avoid an embarrassingly low turnout, government officials and pro-government neighbourhood committees have been warning that people who do not show up for the vote may lose their jobs, essential food subsidies or homes." 

Democracy?
Yeah right.