Sainsbury's Bank is to launch a multi-million pound marketing campaign including in-store promotions to grow its motor book.

The banking arm of the retail giant is thought to be spending up to £20m on an advertising campaign and is looking to offer customers quotes in its supermarkets.

A spokeswoman for Sainsbury's said "Sainsbury's Bank is planning to increase its car insurance marketing activity.

"As part of this process, an additional agency, Walsh Trott Chick Smith, is working closely with the rest of the bank's incumbent agencies to refine some new creatives for car insurance, which could work across a broad range of marketing channels."

The supermarket, which works in partnership with esure, has around 150,000 policies and expects growth of around 20% this year.

Head of motor Joanne Mallon said: "The product itself is not changing. We are just bringing it to more people's attention."