Paul Richards, a former political adviser to former health secretary Patricia Hewitt and former communities secretary Hazel Blears, said ministers reacted more quickly to a letter from the prince than nine-tenths of other correspondence.

Justice secretary Jack Straw is working on plans, proposed by the prime minister, to prevent the publication of all correspondence between royals and ministers under the freedom of information act, extinguishing a slim chance of obtaining letters which currently exists.

...ordered the prince's letters to remain secret because their release could compromise the appearance of his neutrality