In the unlikely event your employer checks they will not find a problem.
A friend whose wife was worried about exactly this asked her company's HR to check to make sure she was not in breach of her visa by working during the application, eventually she got a letter from HR saying everything was cool.
There is some trust here . I have a lot of faith in the sensibilities of the UK system, which has got so much better in the last few years, and will continue to do so. It is an antiquated process with some peculiarities but I am confident of the robust nature of the protocol if you are honest and play by the rules.
Why am I so optimistic? The UK visa is granted if you meet the requirements while other countries (like Singapore) are discretionary. UK follows certain rules and if they make an error it gets rectified. Some other countries turn you down flat despite theoretically meeting all the criteria. For me this puts the UK process right at the top of the pile.
