Through wise investment or pure good fortune you and / or your family have built up a tidy nest egg. Giving 40% of your nest egg to the Exchequer probably wasn't part of your original plan.
But unless you act now that could well be the case. Don't panic, Christies can help. The key to mitigating any potential liability is to take professional advice prior to the event, the earlier the better. (e.g. Inheritance Tax has a seven year rule.)