In an oil-rich country saddled with shortages of food, medicine and such basics as soap and toilet paper, a steady wave of protests against the socialist Maduro and his government has been on for more than a month.

And the death toll from violence at the rallies rose to 29 Tuesday with word from the government that a young man it said had been looting was shot by a shopkeeper in the northern city of Valencia.

Barricades of rubbish and bins blocked streets in Venezuela on Tuesday in big protests that seem likely to intensify after Maduro announced his idea of electing a constituent assembly to write a new constitution.

That body would not include political parties with seats in congress but rather representatives of social sectors such as workers, farmers and other communities.

His plan, announced Monday, has inflamed the opposition, which is calling for even bigger demonstrations to demand elections. Wednesday's rally is being described as a "mega protest."

"The idea is not to consult with the people, but rather for the ruling party itself to choose so as to have a tailor-made constitution," said Freddy Guevara, deputy speaker of the opposition controlled National Assembly.

"We have to up the pressure in the streets," he said Tuesday.

The Venezuelan opposition says the gambit further weakens the chances of holding a vote to remove Maduro, whom they blame for the economic crisis that has sparked the food shortages and rioting.

A presidential election is supposed to be held next year. The opposition has been pushing for months to oust Maduro from power through a recall vote. But that effort stalled.

Polls show that more than 70 percent of people interviewed do not support Maduro, a former bus driver hand-picked by the late Hugo Chavez to succeed him.

The idea of rewriting the constitution, said Diego Moya-Campos of the London-based risk consultancy IHS Markit, "is a desperate measure by a government that knows it cannot call elections because it is going to lose and resorts to polarization."