Hmm, my gut feeling is that this will be initial trade prosecutions of unregistered electricians or tradesmen undertaking electrical work as a minor part of the job they are doing and hoping it slips through unnoticed. I would be extremely surprised if the prosecutions are of DIYers redecorating or doing work in their own homes/gardens.
If you were the council who would you look at first - DIYers, tradesmen or electricians? Not sure who gets the revenus from any prosecution, the government or the council but you can bet whowever it is will make more from looking at tradesmen than looking at DIYers. DIY man gets done for refitting his bathroom, an unregistered sparkie can get done for multiple jobs!
Cheers,
Steve.