I expect you would have to pay VAT at 17.5% plus, possibly, customs duties. I'd suggest trying the customs site at
www.hmce.gov.uk, although this is the sort of site that is a perfect example of how
not to be helpful to the general public; let's just say that "User Friendly" is not in the HMCE vocabulary. However, a bit of digging gave me
a page at HMCE that has a help line phone number.