President Hugo Chavez's allies launched their campaigns Wednesday for crucial congressional elections that come just as recession, crime and inflation have pushed the socialist leader's popularity to a seven-year low.

A survey by the Venezuelan polling firm Consultores 21 indicates just 36 percent of Venezuelans approve of Chavez's performance, the lowest figure since 2003, when Chavez survived an opposition-led strike that devastated the economy, pollster Saul Cabrera said.

The results suggest Chavez allies could face a difficult struggle to keep control of the National Assembly in the Sept. 26 election.

The survey of 1,500 people nationwide in late June and early July had a margin of error of plus or minus 2 percentage points, said Cabrera, who is vice president of the polling firm. He said the poll was financed by a group of private businesses, which he declined to identify.

Chavez's popularity has suffered a decline of 12 percentage points over the past year and a half, Cabrera told The Associated Press.

Critics accuse Chavez's government of severe incompetence and corruption, and many people are unhappy that Venezuela's oil-driven economy remains in a recession while all other South American countries are seeing growth.

Venezuela's inflation rate, at more than 30 percent, is the highest in Latin America.

Cabrera said other problems such as unchecked violence also are contributing to disenchantment with the government.

The new poll indicates Chavez is still popular among the poorest segment of Venezuelans, garnering about 60 percent support in that group, but he no longer has a majority in the other four income categories, Cabrera said.

The pollster said that in spite of Chavez's low popularity level, the president remains a "formidable political competitor" against an opposition that — while it has made some gains — still has not shown sufficient strength to fully capitalize on the situation.

Chavez, who is up for re-election in 2012, has warned his supporters that opposition control of the National Assembly would undo some of the government's efforts toward socialism.

The National Assembly has been predominantly pro-Chavez since the opposition boycotted legislative elections in 2005.

Opposition parties they took to the steets along with Chavez supporters Wednesday as the election campaign officially began.

Several opposition candidates campaigning near the National Assembly building in downtown Caracas were scattered by National Guard troops who fired tear gas at them for purportedly causing a public disturbance. There were no injures or arrests reported.