It's not clear from your question whether you're referring to cabin baggage or hold baggage.
As far as cabin baggage goes, Jrtv is correct. The rules are the same for all EU airports:
http://www.dft.gov.uk/stellent/groups/dft_tran ssec/documents/page/dft_transsec_613514.hcsp
However, there's nothing to stop you from buying some booze in Spain and putting it in your checked-in luggage. Because you'll have paid duty & VAT in Spain, you can bring back as much as you like as long as it's for your personal use (or as genuine gifts for which you receive nothing in return).
Spanish customs won't care how much you take out. HMRC do issue guideline figures as to the maximum amounts which they would regard as acceptable imports 'for personal use'. However, these are largely irrelevant when you're travelling by air because you can't even get anywhere near these 'maximum' amounts without vastly exceeding your baggage allowance:
http://customs.hmrc.gov.uk/channelsPortalWebAp p/channelsPortalWebApp.portal?_nfpb=true&_page Label=pageTravel_ShowContent&id=HMCE_PROD_0102 21&propertyType=document
Chris