The civil service is an institution ‘in play’ under the present administration, but let us not forget that the civil service, however imperfect, is one of the great institutions of state. For 160 years, it has been a bulwark of stability, through political upheavals, progressive enfranchisement of the people, the Kaiser, the General Strike, the Great Depression, the Second World War, Butskellism, the Thatcher revolution, and now Brexit. It provides for swift changes of government, with minimal disruption and has commanded the confidence of the main parties. In our zeal to galvanise a new Whitehall, we must be careful for what we wish for. We may find parts of the system politically resistant, but we must take care not to throw babies out with bathwater. In all the disputes about the UK constitution arising from Brexit – the latest being the dispute about the status of international law – there is remarkably little common understanding about what we mean when we talk about the UK consti...