The shares tumbled 9p or 3.3% to 267.8p as UBS claimed that the average hit to profits in shops would be around 40% after assessing a number of regulatory outcomes.
Beleaguered tech firm Laird enjoyed a rare day in the sun, rising 9.68p, or 7%, to 154.18p after showing signs the business had stabilised following a shock profit warning in October that forced the business to shelve the divi.
The company, which designs antennas for iPhones and Samsung handsets, said it secured an extension to its debt covenants at the end of last year as a precaution.
Meanwhile, North Sea oiler EnQuest strengthened 1p to 50.25p after buying a 25% stake in the Magnus field from BP for $85 million, which will be funded by cash generated from the assets.