I must admit I don't know the answer to this, but I would have thought it was the same as if you sold it and received the cash, and then reinvested the proceeds in the UK. The reason being, that the consideration( i.e the property you receive in settlement) has a fiscal value, and therefore its just a financial transaction at the end of the day. So normal transfer tax, notary fees, and capital gains if applicable ( see Campasols posts).
Just checked the HMRC website, and if the transaction was in the UK, then it would be as I posted, so my guess is Spain would be the same
This message was last edited by Kathyslad on 15/10/2013.