STEP back in time to the Cold War and come face to face with the reality of a nuclear attack at a new exhibition at The National Archives in Kew.

The Secret State is based on recently released top secret documents held in the government archive.

The curator of the exhibition, Professor Peter Hennessy, a long time expert on Whitehall and the Cold War, has uncovered many of the documents during research for his book on the subject.

Sarah Tyacke, chief executive at The National Archives, said: "This exhibition is riveting because the details captured in the secret files make you realise just how vulnerable the whole world was. I'm thrilled that this exhibition is going to allow people to take a closer look at the covert comings and goings of the war that was quietly fought all around us."

Professor Hennessy said: "The National Archives shelves are the place where virtually all the most terrifying files portraying what was likely to happen to Britain in the last hours of peace - and the first hours and days of the nuclear holocaust if World War III had broken out have come to rest."