The voltage difference won't screw with your camera battery if you have the proper equipment. Check your battery charger-- it's probably already rated for multiple voltages, especially if it's a proprietary battery (i.e. it came with the camera, not AA rechargeables or the like). It should say 110-220 v or something like that. If it *doesn't*, you could pick up a voltage converter but they're not terribly cheap.
Please note that plug adapters-- which you will need-- are NOT the same thing as voltage converters. The UK and continental Europe have two different plugs so you'd need to pick up one of each if you're going to be in both places.