William Hague regales us with the Euro Mouse Theory. This notes that, genetically, a mouse is 90 per cent the same as a human. So it’s only the extra 10 per cent that really counts. The Lib Dems (inventors of the Euro Mouse Theory) believe that the Lisbon treaty may be only 10 per cent different from the original. Thus the fence. Mr Hague, eyes fixed on the Lib Dems, noted: “The difference between a man and a mouse is, indeed, a fascinating question.