If you're interested in the social background to your family history, then read on.
More than half a million pages of key British Cabinet papers, from 1915 to 1977 are now available to search and download for free at www.nationalarchives.gov.uk/cabinetpapers. The digitised records comprise: Cabinet conclusions; Cabinet memoranda; precedent books and available secretary’s notebooks.
Chances of finding an ancestor named are slim. You could get lucky if, say, your family member is mentioned as having taken up employment in a government agency, perhaps even as a secretary.
More likely is finding mention of a major event or movement in which your family member was involved. You may also find information on a wartime incident that was not covered in a timely manner, or at all, in the newspapers owing to censorship, for example, detailed lists of ships sunk. I was surprised at how often Canada is mentioned.
There is detailed supporting material on the website including a short podcast Cabinet by Laura Withey (Project Manager) and Dr. Ed Hampshire (Records Specialist.)
It's quite a rigmarole to order and download the papers through the Documents Online facility. At present there's no charge to do so. Making the documents available through Documents Online suggests that could change.