The 1st edition of this seminal text was written as a response to the constitutional crisis of 2009, sparked by the 'expenses scandal', which led a general distrust of the UK's entire political order. A decade on, it is no exaggeration to say that the situation has dramatically deteriorated. The UK's constitutional order faces an existential crisis, with Brexit placing unbearable pressure on the political and legal architecture. All this makes the need for a written Constitution more pronounced. Retaining the easily accessible style of the first edition, this book addresses how this might be put in place. Part 1 sets out a number of arguments in favour of a written Constitution, as well as the most common objections. Part 2 presents a working draft in the form of one possible model for a Constitution. Observations and explanatory notes are attached to each section of this draft Constitution. This model Constitution is intended as the first stage in a public debate, designed to provoke further discussion about the content and method of legislating into law a written Constitution. Part 3 contains the draft of the Act of Parliament that would be needed to introduce any form of constitutional change. Rarely has a book been more timely or essential.