I have gleaned more details by talking (off the record) to a PRO official in another department. I understand that MI5's in-house history covering the First World War, some fifty volumes, will be released into the PRO in mid-November and that a BBC Timewatch documentary based on this is being prepared. Next year we can expect to see MI5 material from the Second World War and then from the inter-war period.
However, my source described the whole exercise as a "sop", warning that the files to be released will reveal little of MI5's real history.
Would the PRO care to tell us, on the record, what exactly is going on?
Christ Church College