Yes Ofcourse!It is called EASA license for a reason.Since Spain is under EASA you would be able to fly an EC- registere a/c on your UK license.The A320 type rating can be revalidated/renewed by a UK examiner or any other EASA examiner(provided he undertakes a briefing from the UKCAA).You can fly on a UK license in spain and there is no need to convert unless the operator wants you to do so.
Hope this helps.