This is VAT
(Value Added Tax) which is added to all consumer products in the UK. Previously protein supplementation came under the neccesary food category, and was exempt from tax. However the new government has decided to shift it from food to consumer product. The only possible way this can be seen as acceptable in the (general) public eye is to try and play on the fears and prejudices of the average man on the street. That excessive protein leads to health issues and anger problems, muddying the waters between protein/creatine and illegal steroids even further to the layman.
This is a very transparent attempt at diversion, but it will pass and people will start talking about anger issues and health issues from excessive protein in due course. I predict Jeremy Kyle will have someone on his show within a years time who has gotten in trouble with the law over 'protein rage'.