The TV offensive, the first by Banks Hoggins O'Shea/ FCB since the agency picked up the business in November last year, is a back-to-basics approach reminding consumers of Weetabix's benefits.
The new strategy is reflected in a 30-second commercial, which parodies an 80s ad for a power company.
It opens with the camera rising above the white cliffs of Dover and flying across the countryside and suburbia while a voiceover boasts that "we produce an energy that's reliable, clean and efficient".
It ends with three Weetabix forming an electrical plug.
Rob Fletcher and David Alexander, the agency's joint creative directors, produced the commercial, which was shot on location in Spain and the UK by Mike Stephenson for Moon.
PHD is planning and buying media for the campaign, which breaks on Saturday supported by 96- and six-sheet posters.
Weetabix amazed the industry when it aligned its £16 million above-the-line assignments into Banks Hoggins, abandoning the high-profile work produced by Lowe.
However, company chiefs believed the advertising had become removed from the product and a new approach was needed to overcome problems in a sector damaged by changing breakfast habits.
Bill Humes, the Weetabix commercial director, said: "Highly successful campaigns such as 'Have you had your Weetabix?' are still remembered. We intend to remind consumers of the core benefits of a Weetabix breakfast."