Caracas (AFP) - More than 80 percent of basic consumer products including food and medicine are now in short supply in Venezuela, a poll says.

Stores are facing greater shortages than households, president of pollster Datanalisis Luis Vicente Leon said Friday.

But the company's latest study, with data from April, saw a jump in that index as the oil-rich country grapples with political and economic crisis.

"The deterioration has been exponential over the last two months," Leon said. "We are seeing indices worsen in a really dramatic way."

Datanalisis expects inflation of 450 percent, and predicts purchasing power will drop by at least 40 points compared to 2015.

The latest official inflation figures from December 2015 reported a 180.9 percent increase in prices.

The combination of shortages and inflation plaguing Venezuelans has forced at least two-thirds of the population to rely on the black market for basic goods.

Around 86 percent of Venezuelans polled pinned blame on President Nicolas Maduro's leftist government.

Maduro claims that a conspiracy of entrepreneurs are waging "economic war" on his country, and also says the collapse of prices of oil -- a commodity that accounts for 96 percent of Venezuela's hard currency revenue -- has provoked the crisis.

According to Datanalisis, 71.8 percent of Venezuelans think Maduro's "economic war" theory as "little or no credibility."

The study surveyed 800 people in eight major Venezuelan cities of varying socioeconomic status. The margin of error was 3.46 percent.