Sainsbury's Bank, a joint venture between the supermarket and Halifax Bank of Scotland, partnered with Esure for its car insurance product, which is promoted in the campaign created by Walsh Trott Chick Smith.
The campaign consists of TV, in-store promotions, direct marketing and digital marketing, all featuring Little Bill and developed around savings that the group says its insurance can provide.
Walsh Trott won the £15m account in October 2004 after a three-way pitch with St Luke's and Abbott Mead Vickers BBDO.
The TV spot launches this week and features an animated character called Little Bill, who struts down the street singing. He proceeds to walk around town waving at a variety of people explaining how he can save them money on their car insurance.
The music in the background is 'Big John' with the words changed to Little Bill. At the end of the ad, Little Bill walks off into the sunset.
The ad has been art directed by Gordon Smith with the copywriter Dave Trott. The animation was done by Passion Pictures and Little Bill's voice is provided by Roland Rivron.
Jonathan Hewitt, director of insurances at Sainsbury's Bank, said: "The car insurance sector is one of the most competitive in retail financial services.
"We have a market leading product that offers a great combination of competitive premiums and quality cover and hopefully with our new TV advertising, we can take this message to a much wider audience."
Sainsbury's Bank has estimated that the car insurance sector's adspend could top £200m for the first time, based on spend between 1999 and 2004.
Will Hamilton, marketing director at WTCS, said: "Sainsbury's car insurance is all about competitive premiums, quality cover and good service and our brief was to create a memorable and friendly character that encompasses this. Little Bill does this and he also provides a strong link to the supermarket.
"We believe that he is a very engaging character and we have had some very positive research back from consumer groups in terms of how he is perceived."