[Osem]

So far as avoidance goes, I'd have thought prosecutions are always going to be more problematic than just securing the repayment of tax owed because the boundaries between what's acceptable avoidance and what isn't (i.e. what's legal and not) have to be tested before any scheme can be declared illegal. To be successfully prosecuted, I think there'd need to be proof that those involved in schemes which have been judged to be illegal after the event were fully aware of the illegality beforehand.