I tried for over a year to obtain from MI5 its files on the ex-Communist anti-imperialist campaigner George Padmore, who died in 1959. The final word from MI5 was that they could, by law, release any files they might have. However, as they were not obliged to do so, they would not.
The only explanation offered was that national security and agents might be jeopardised. The former is ridiculous. As for the latter, why not ink out the agents' names (if they are still alive), as is done, for example, in the USA?
Senior Research Fellow
Institute of Commonwealth Studies
University of London