On Wed, 4 Aug 2010 04:04:59 -0700 (PDT), "Man at B&Q"
wrote:

Prices displayed to consumers *must* include VAT inclusive prices with
equal prominence to ex-VAT prices (price marking order 2004).

There's probably some loophole that allows some traders to get away
with not doing so, like requiring you to be members of their club, or
giving you an account number and deeming you to be a business
customer.

Not a few websites will do this, log in as a business customer and you
get the ex-VAT prices (with the VAT added alongside), log in as a
public and you get the VAT inclusive price (with the ex-VAT alongside)

Still nothing that prevents wholesalers selling to the public.

AFAIK no law, but they can choose not to.