This parliamentary written answer has been drawn to my attention (apologies to who did so: I have forgotten who it was so can't give credit):
Note that last comment. What does 'the Government recognises the case for publishing country-by-country reports on a multilateral basis' mean? For all we know it might be 'When the Cayman Islands agree that this is a good idea we will do it'. In fact, I suspect that is the case.