Quick! Get the customs people round to Welshwil's house! We've discovered a master smuggler!
Travellers from
most EU countries are permitted to import a theoretically unlimited number of cigarettes (for personal use only), without paying duties or taxes. Her Majesty's Revenue & Customs apply a 'guideline maximum' of 3200 cigarettes, as the quantity which they'll assume are solely for personal use unless there's evidence to the contrary (such as importing lots of different brands).
However there are transitional arrangements relating to those newer EU countries where duties are currently very low in comparison with the majority of member states. The 'unlimited/3200' rule will not apply to those states until they bring their taxes on cigarette products into line with other member states (which they've committed to do). Until then, the limit is 200 cigarettes.
If Welshwil had been caught, he could have been charged a large amount of tax and duty (probably making the cigarettes dearer than if purchased in the UK) or, more likely, he would have simply had all of the cigarettes confiscated. (Theoretically he could also have been prosecuted but that's not actually very likely).
The relevant rules are on the HMRC website:
http://customs.hmrc.gov.uk/channelsPortalWebAp p/channelsPortalWebApp.portal?_nfpb=true&_page Label=pageTravel_ShowContent&id=HMCE_PROD_0095 60&propertyType=document
Chris