The "hippy campaign consists of 48-sheet posters, which go up at the beginning of August and will run nationally in a bid to boost the brand's presence in the minds of consumers over the key summer barbecue period.
"Hippy may also be rolled out in the US and Canada.
Media planning is through MBS, with media buying handled by Carat.
One poster shows a woman seated in front a holy shrine, about to bite into a dripping burger. She has blindfolded the deity, to make sure it is not offended. Another shows a loon-pant-clad man choosing a steak in the supermarket. He is wearing a fake nose, glasses and moustache in a bid to remain anonymous.
The final poster features a bearded man interrupted by his angry girlfriend just as he is about to eat an enormous plate of sausages. All ads feature the strapline: "There's no resisting the bite of an HP burger/sausage/steak."
MML's joint creative director, Andy Amadeo, said that the campaign was designed to appeal across a wide range of consumers: "The idea will cross borders, and isn't restricted to one territory - hippies have an enduring appeal wherever you are in the world. It was important to use a vibrant visual idea to demonstrate the assets of HP Sauce, and the 48-sheet poster format was thought to be the best in this case."
HP Sauce, recently voted one of Britain's greatest brands, is owned by Danone, which spends about £10 million on its HP Foods brands, which include Amoy, Lea & Perrins and Daddies Sauce.
HP hired MML in 1998 to help boost sales of HP Sauce, which was increasingly seen as old fashioned as consumers turned to ready meals and other new products. It previously employed Young & Rubicam, using a long-running TV campaign starring the boxer Frank Bruno.
The campaign was written by Kirsten Everett and art directed by Kwai Mak. It was illustrated by Peter Loveday.