If you're searching for a Walther PPK CO2 replica in the United Kingdom, you'll quickly discover that these realistic air pistols are effectively banned from sale. The restriction stems from the Violent Crime Reduction Act 2006, which prohibits the manufacture, import, and sale of realistic imitation firearms (RIFs) – defined as any device that closely resembles a genuine firearm.
Because the PPK CO2 gun is a near-exact visual copy of the iconic Walther PPK pistol (famously carried by James Bond), it falls squarely into the RIF category. UK law allows only "two-tone" or brightly coloured airsoft guns (where at least 51% of the surface is a non-military colour) to be sold without a specific defence. Since the PPK replica is typically finished in realistic black or metal tones, it cannot be legally retailed to the general public.
Always verify current regulations with the Home Office or a registered firearms dealer before attempting any purchase, as laws can change and penalties for non-compliance are severe.