Cadbury Dairy Milk is giving consumers the opportunity to post a message to Britain’s Olympic athletes.

Rolling out next month are limited-edition bars of Dairy Milk in a cardboard box featuring a Union Jack design. Inside the box is a pre-paid and pre-addressed postcard that can be used to send an encouraging message to Team GB.

Every consumer who submits a postcard will be entered into a prize draw to win one of 150 pairs of tickets to the official Team GB launch concert at the Royal Albert Hall, London, in May. In addition, Kraft will be giving away one million Clap-Banners - which can be held up at a sporting event as a banner or folded up and used as a noisemaker.

Consumers can also submit messages to Team GB on a dedicated website, where they can enter the prize draw by typing in a unique code inside each pack.

The campaign is being supported with digital, radio, press and outdoor advertising, as well as PoS that in larger stores will include branded post boxes.

The packs available in the cardboard packaging are 120g (rsp: £1.39) and 230g (rsp: £1.99) bars of Dairy Milk, Fruit & Nut, Wholenut and Caramel, and 230g packs of Turkish. Dairy Milk will also be sold in a £1 price-marked 120g pack.

The activity was inspired by a postcard campaign run by the British Olympic Association during the 2010 Winter Olympic Games in Vancouver, said Norman Brodie, general manager for London 2012 at Cadbury owner Kraft.