Yes, business meetings (and the things in this spirit) are the exceptions. However, you certainly cannot say "I feel like doing my normal job in London this wee

Yes, business meetings (and the things in this spirit) are the exceptions. However, you certainly cannot say "I feel like doing my normal job in London this week". Now, let's say you go to London for one important meeting and spend the rest of the day working as you don't want to waste your time, ok, no one is going to ask questions. But, if you go to London for one meeting and work there for the rest of the month, you are in clear violation. Is anyone going to hunt you down? Probably not. Are you breaking the intent of business visas? Definitely.