Because some people just don't seem to get it:
(Sets are sized for clarity of explanation, and I'm not making any assertions about the overall proprtion of election advertisements which are attributable, or of Parliamentary advertising which is election advertising, or whether attribuable expenditure is within the Parliamentary spending rules. What I am asserting is that the view of some politicians and journalists that Parliamentary expenditure cannot be election advertising and therefore needs not bear a promotor statment is incorrect).