The D-Notice Affair of 1967 is of critical importance when examining British secrecy. The affair, which began when Chapman Pincher published a story reporting that private cables and telegrams were being scrutinised by security authorities as a routine measure, dominated headlines and national political discourse for six months. Marcia Williams, who served as Harold Wilson's political secretary for nearly thirty years, including his eight years as prime minister (1964–70, 1974–6), commented in her memoir Inside Number 10: ‘We all became obsessed with the matter . . . The whole lamentable affair had hung like a heavy cloud over us for many months. It had sapped the energies of the Prime Minister and his morale. We felt deeply concerned for him.’ The affair has a genuine claim to be considered the British Watergate. Rarely has a prime minister stirred as much angry reaction among not only the press but also political allies and opponents as Wilson did with his clumsy handling of the case. In an apparent personal epiphany, Wilson later observed that his behaviour had been ‘gratuitous’ and amounted to what he regarded as ‘one my costliest mistakes of our near six years in office’. His first error was to threaten the Express with legal action for publishing a ‘sensationalised and inaccurate’ story in plain defiance of D-Notices; his second was to reject the verdict of a committee of privy councillors called – by the prime minister himself, no less – to investigate the matter. The consequence was a series of hostile parliamentary debates and what newspaper tycoon Cecil King estimated as the ‘worst press any Prime Minister has had in my day’. Behind closed doors, Wilson's Cabinet colleagues were utterly dumbfounded by what they had seen. The Minister for Transport, Barbara Castle, was ‘appalled’ and proposed that he had ‘gone off his rocker’.