Cyprus has been a member of the EU since 2002. Therefore, you're entitled to import an 'unlimited' quantity of cigarettes, as long as they're for your 'personal use'. (The definition of 'personal use' includes genuine gifts, for which nothing is expected in return but excludes cigarettes for which you'll receive something in exchange - such as cash).
HMRC have guideline maximum figures for imports from the EU, below which they're unlikely to challenge you about whether the imports are for personal use. For cigarettes, the 'guideline maximum' is
3200. If you go above that figure, you might be challenged about your reasons for importing them.
It should be noted, however, that bringing back several different brands might also alert HMRC to the possibility that the imports are not all for personal use.
http://customs.hmrc.gov.uk/channelsPortalWebAp p/channelsPortalWebApp.portal?_nfpb=true&_page Label=pageTravel_ShowContent&id=HMCE_PROD_0102 21&propertyType=document
Chris