I believe the ones at ASDA are madcatz so not orginal, reviews of them say they are not the cleaver.
Instore only Asda selling unofficial Wii Nunchunk for £5 and Wii remote for £15 - Page 2 - HotUKDeals Forum
I would (As I Did) Buy the game Wii Play and get a remote with that, mabe gameshops in town will do a pre owneded one or try ebay.
Here is what I mean.
Play.com (UK) : Wii Play (includes Wii Remote) : Nintendo Wii - Free Delivery