You're theoretically allowed to bring back an unlimited amount of 'duty paid' alcohol from any EU country, as long as it's for your personal use. ('Personal use' includes bona fide gifts to others but not booze which you will sell to someone else, irrespective of whether you make a profit or not).
However, HMRC will challenge travellers bringing in excessive quantities. If they're not satisfied that the booze is for personal use, they'll confiscate it (and possibly the vehicle as well). They could also bring a prosecution for attempting to evade duty.
In order to provide travellers with guidance, HMRC advise that they'll be particularly suspicious if the following quantities are exceeded:
110 litres of beer, 90 litres of wine, 10 litres of spirits, 20 litres of fortified wine.
http://customs.hmrc.gov.uk/channelsPortalWebAp p/channelsPortalWebApp.portal?_nfpb=true&_page Label=pageTravel_ShowContent&id=HMCE_PROD_0102 21&propertyType=document
Chris