House of Representatives. These arrangements, however, are only hinted at in the text of the Constitution. There is a requirement (section 64) that the "Queen's Ministers of State", who are nominally appointed by the Governor-General, be or swiftly become members of either House of Parliament. The existence of the Prime Minister and Cabinet, and the requirement for them to have the confidence of the House of Representatives, are not mentioned. Nonetheless, these have been fundamental features of Australian constitutional practice from the start. More recently, the principle of responsible government was reinforced by the High Court of Australia which upheld orders for a Minister of the government to table documents in the NSW Legislative Council after he refused to do so. Separation of powers The Constitution features a distinct separation of powers. Legislative power is dealt with in Chapter I, and is vested in the Federal Parliament (section 1). Executive power is dealt with in Chapter II, and is vested in the Governor-General as the Queen's representative (section 61). The judicature is dealt with in Chapter III, and is vested in the Federal High Court and "in such other federal courts as the Parliament creates, and in such other courts as it invests with federal jurisdiction" (section 71). However, the Queen is an element of the Parliament as well as being head of the executive; and the Ministers of State who "advise" the Governor-General are actually required to be or become members of Parliament. While there is no significant separation of the legislative and executive powers (the "political branches"), the High Court has developed an increasingly stringent doctrine of the separation of the judicial power from the other two. Direct election to both Houses of Parliament The Constitution required direct election of members to both Houses of Parliament from the beginning (sections 7 and 24). This was a novelty at the time, since the national upper houses with which the framers were best acquainted were chosen by other means: indirect election by the State legislatures (United States Senate before the Seventeenth Amendment in 1913), executive appointment for life (Senate of Canada), or a combination of appointment for life and hereditary succession (British House of Lords). Referendum for constitutional amendment The text of the Constitution was not presented to the British Parliament for formal enactment until it had been approved by the electors of the colonies. On the same principle, any