The Guardian has revealed that Prince Charles has received confidential Cabinet papers for decades, making him Britain's "best informed lobbyist".
Confirmation came from the Cabinet's "precedent book", which was locked away "cupboard within a locked office in a secured corridor inside the Cabinet Office".
The Cabinet Office fought for three years against the release of the documents, which came after a request from Republic, the campaign for an elected head of state.
The document reads: "The standard circulation for Cabinet memoranda includes the Queen, the Prince of Wales, all members of the Cabinet, any other Ministers in charge of departments (or to be treated as in charge of departments)".
Prince Charles has long been accused of interference in political matters and the Guardian's release of the 'black spider' memos revealed the extent of his lobbying in personal letters to ministers.