I am a "boss". I often have to ask my staff to work beyond their contracted hours. Unlike Keith Woollacott, however, it is very unusual for them to refuse (Working 9 to 5, letters.computing.co.uk).
The reason? They know that I would not ask unless necessary and that it is required for the project.
In turn, I take this into account in their appraisals.

Keith Woollacott should not be at all surprised to find that his "work to rule" approach will end up costing him far more than £5,000 per year as he is awarded minimal pay rises and is overlooked, yet again, in favour of one of his harder-working colleagues.

Philip Lewis