Media roundup: junk-food ads, London 2012, Tesco, River and Virgin Holidays

We bring you the buzz from the wider media sphere, across the world and across the web. This week: government rejects junk-food ad ban; marketers warned over 2012 ambush tactics; Tesco adds AR to Price Drop campaign; Tullamore Dew unveils global ad; River and Virgin revamp Rock and Roam.

Government rejects calls for ban on junk-food advertising The government has dismissed calls to tighten the rules over food ads only a week after news that Downing Street is considering a ban on all ads aimed at children.

Marketers warned over 2012 ambush marketing conviction threat Marketers face a heightened risk of gaining a criminal conviction if their brand appears in ambush marketing during the London 2012 Olympics.

Tesco mixes augmented reality into Price Drop push Tesco is piggybacking mobile content on a big print and outdoor campaign intended to bombard consumers with its £500m Big Price Drop initiative.

Tullamore Dew unveils fresh global ad campaign William Grant & Sons is rolling out a new global ad campaign for Tullamore Dew as part of a wholesale revamp of the Irish whiskey brand.

River and Virgin Holidays present the re-designed Summer 2011 issue of Rock & Roam Rock and Roam revamped.