The CDPA does not explicitly protect fashion designers. Whilst it protects artistic work, there is no mention of fashion directly and it's difficult for brands to prove originality as very little is seen as original. The act needs amending to protect small businesses from fast fashion brands!
You may be interested in these active petitions
Fast fashion brands get away with stealing the design's of small businesses as a result of this. There isn't much within the UK laws that govern these incidents. Whilst social media helps to spread awareness, the cost for small businesses to take larger companies to court is unrealistic for them. Understandably, people are inspired by other designers within the industry, but there should be laws to protect the outright copying of designs. The lack of protection is damaging the industry.