I very much hope this isn't too late. But this is a stock problem question of the UK not implementing a directive in time. I won't do it all for you but you need to consider State Liability. Basically, in Francovich v Italian Republic, it was held that where (i) the result prescribed by the Directive entails a grant of rights to individuals and; (ii) the contents of these rights are identifiable and; (iii) there is a causal link between breach of the obligation and the loss suffered, damages are available. This test was elaborated (don't mention what I just said in the problem but you can if you are not up to the word limit - this shouldn't be a problem anyway!) in Brasserie du Pecheur where it was said that damages are available where: (i) infringed law was intended to give rights to individuals; (ii) the state's breach was serious; and (iii) there is a causal link. So it's similar but (ii) is modified. For your purposes, look at Dillenkofer, which says that if a state does not implement a directive within its time frame this is a serious enough breach. The other two criteria seem to be satisfied.
Good luck.