Most tax advisers would take it for granted that the way parliamentary legislation is drafted is somehow set in stone. Most would also agree that the fundamental principle involved is the quest for what is called ‘legal certainty’. In the Ramsay case (1981), Lord Wilberforce said: ‘A subject is only to be taxed upon clear words, not upon “intendment”, or upon the “equity” of an act. Any taxing act of parliament is to be construed in accordance with this principle.’

But is this