Security guard for the poster that really is good enough to eat

The poster looked good enough to eat - and it was when the world's first edible poster was unveiled in London yesterday.

The 12ft-long chocolate-coveredbar from Cadbury's was almost 30 times its original size, weighed 100kg and required three men to carry it.

The gigantic bar was made from 40kg of chocolate and 22 gallons of milk - the equivalent of milking a cow for 10 days. It marked the relaunch of the Snack Wafer brand in the UK and a comeback of the 30-year-old advertising slogan "Bridge That Gap With Cadbury's Snack".

The poster site on Vauxhall Bridge was patrolled overnight by security guards. Tony Bilsborough, spokes- man for Cadbury's, said: "Although the weather isn't hot enough to melt it, we're taking it down later. We don't want to tempt people into gorging on this massive spectacle."

The edible campaign was to be replaced by a 3D imitation later in the day. A further 650 poster sites across Britain are being erected today at a cost of pounds 2m.