But much more is being kept hidden. Why, for example, are we not permitted to read about the accident at Windscale in 1957? Even 80-year-old files, on subjects such as the Irish Troubles, remain secret.
The wide exceptions to the 30-year rule sanctioned by the authorities amount to blanket censorship far beyond national security concerns. Things do not have to be like this; the US Administration, with a 20-year rule, has released papers on to the Internet relating to scandals such as the FBI's investigation into the assassinations of John and Robert Kennedy.
Our system is a mess. The impetus for reform given by the Cabinet Office under William Waldegrave and David Clark is being lost. At a time when the government's commitment to Freedom of Information hangs in the balance, secrecy about ancient controversies is a worrying sign.
Legislating for a 10-year rule is the least the public can expect, since these records really belong to them. At the same time, the Royal Archives at Windsor, a vital historical resource, should be placed under public control. It is ludicrous that papers relating to the illness of George III should remain locked up. Open government is one of Labour's most important pledges; if they cannot pass this test, future historians may judge them harshly.