If you don't mind importing, you can currently buy an Xbox One White Sunset Overdrive bundle for just £233.20.
It's a stonking deal that includes UK shipping, but you'll have to sort out a power adaptor or a new cable (thankfully it's pretty standard - you're talking a quick trip to Maplin and won't have to buy a new power brick). You'll save £12 versus the cheapest UK deal we can find.
Preparationiskey found this a few days ago on HUKD (thanks again!), but we're posting it now because, for a few glorious minutes, there were rumours of an even more colossal price drop. Rumours that turned out to be a bit wayward, but hey, I'd already half-written the post so at least it won't go to waste.