You will need a transformer from 220 to 110V, lest you want to blow it up.
I was born and raised in Madrid, but went to school in an American air base outside the city. My father worked for the Dept. of Defense and used the base exchange to buy our appliances and stereo equipment (110 volt). Back then, the stereo didn't allow you to select the voltage in the back and the fridge and washer didn't have that option, therefore we had to use voltage converters (or transformers) to be able to use them on the Spanish economy (220 volt).
You can purchase a converter on Amazon.co.uk for about 13 pounds...
Step down voltage converter 240V - 120V 100W: Amazon.co.uk: Electronics
Hope that helps!