Apple doesn't and to be honest, I would be surprised if anyone else that did. I'd be inclined on asking on UK student forums like thestudentroom, to double-check.
I think your best bet would be to buy from either Argos while they're offering a free £10 gift card with purchases over £100 or Currys who are offering a free £15 iTunes card with any iPod Nano.
If you have an NUS Extra card, you can get a 5% discount from Amazon. They seem to be the cheapest place for iPods most of the time anyway, so thats what I would recommend.