Peter Hennessy, Professor of Contemporary History at Queen Mary and Westfield College, London, said yesterday: "One aspect of Wilson's place in history which was overlooked when he died was what he did for the study of history itself. If it had not been for Harold Wilson taking the lead, both within his Cabinet and in Parliament, in reducing the 50-year rule for secret documents to 30 years, we would only now be beginning to look at classified state material for the post-war period."
Wilson's memorandum to the Cabinet argued that the earlier release of papers could "promote a more informed public understanding of contemporary issues and contribute to the greater efficiency of current policy-making and administration".
But there were also less elevated motives. Most of the "advance of our Colonies" towards independence had taken place in the previous 40 years and, "if we do not write the history of this process, the newly independent governments of those countries will". A 30-year rule "might also help to reduce the embarrassment in which we sometimes find ourselves in relation to the practice of the United States government, who are considerably more generous in allowing access to their documents than we are to ours and whose records include a number of documents originating in this country, to which historians can obtain access in the United States but not here".
In a radio interview with Professor Hennessy in 1985, Lord Wilson said he had wanted to reduce the "closed period" to 25 years, but that Ted Heath, whom he consulted as Leader of the Opposition, did not agree. Wilson said: "He wanted 50. Then I said, 'Well look, we obviously don't agree. I'm going to make this an election issue in the next election.' He then not very happily accepted 30."
The 30-year rule was enacted in 1967, and came into effect in 1972. "But for Harold, this annual dash to the Public Record Office to unearth bucketfuls of delayed scoops simply would not be possible," Professor Hennessy said.