A revealing one-off documentary that provides an inside view of how Tony Blair and former prime ministers - including Harold Wilson, Margaret Thatcher and John Major - have run their cabinet, the highest decision-making body in the land. Through candid interviews, rare archive footage and filming inside No 10, presenter Michael Cockerell opens the door to the Government's own chamber of secrets as he seeks the answer to the question: is the notion of cabinet government an obsolete concept?