It will not appear on any listings and will pounce without warning, day or night, on to the airwaves: first a harp playing folk music, then a familiar voice.

Welcome to Suddenly Chávez, Venezuela's newest radio show and the latest effort by the country's loquacious president to talk to voters, whether they want to listen or not.

"When you hear the pluck of a harp on the radio, maybe Chávez is coming," he said on the inaugural show yesterday. "It's suddenly, at any time, maybe midnight, maybe early morning."

And maybe something to do with the fact few listeners and viewers tune into Hugo Chávez's long-running Sunday radio and TV show, Alo Presidente, which starts at 11am and lasts up to eight hours.

Chávez seems to have calculated that ambush will catch a wider audience that may have tuned into the state-run Venezuelan National Radio for a baseball game or salsa music. Venezuelans are already accustomed to him interrupting scheduled programmes through a law which forces all radio and TV stations to transmit live those speeches he deems important. Cable channels used to be exempt – prompting a surge in demand from viewers seeking respite – but the government has moved to close that loophole.

In addition to a weekly newspaper column, the president also regularly phones a late-night pro-government talkshow, The Razor Blade, to assail critics and make policy announcements.

With legislative elections looming, Suddenly Chávez appears designed to use the president's charisma and communication skills to woo back former supporters fed up with rampant crime, inflation and crumbling public services.

"We have many things to report," he said, and kept listeners' attention with a dramatic announcement. "I call on the whole country: 'Switch off the lights.' We are facing the worst drought Venezuela has had in almost 100 years."

Venezuela, a member of South American Opec, has some of the world's biggest oil reserves but uses hydroelectricity for 70% of its power. With rivers and dams drying up, blackouts have hit much of the country. "We are ready to decree the electricity emergency, because it really is an emergency," said Chavez.

Under the decree, Venezuelans who use more than 500 kilowatt-hours of electricity a month must cut consumption by 10% or face a 75% price increase. Chávez said he would set an example by cutting power usage at the presidential palace.