What does UK law say about faking online reviews?

Although there is no specific law in the UK that prohibits publication of fake online reviews, the Consumer Protection from Unfair Trading Regulations 2008  prohibits unfair commercial practices and faking online reviews is not doubt unfair.

Under UK law you can be prosecuted for faking  onlne reviews but so far there has not been any significant prosecution in this respect.  – See more at: http://www.internetlawcentre.co.uk/is-it-illegal-to-write-fake-online-review-uk