Fusion of powers is a feature of some parliamentary forms of government where different branches of government are intermingled or fused, typically the executive and legislative branches. It is contrasted with the separation of powers[1] found in presidential, semi-presidential and dualistic parliamentary forms of government, where the membership of the legislative and executive powers cannot overlap. Fusion of powers exists in many, if not a majority of, parliamentary democracies, and does so by design. However, in all modern democratic polities the judiciary does not possess legislative or executive powers.
The system first arose as a result of political evolution in the United Kingdom over many centuries, as the powers of the monarch became constrained by Parliament.[2] The term fusion of powers itself is believed to have been coined by the British constitutional expert Walter Bagehot.[3]
Australia has a partially Westminster-derived parliamentary system in which the executive branch is entirely composed of members of the legislative branch.[4] Government ministers are required to be members of parliament—but the federal judiciary strictly guards its independence from the other two branches.[5]
Canada, like other parliamentary countries using the Westminster system, has a fusion between the executive and the legislative branches, with the Prime Minister and other Cabinet ministers being members of Parliament. Senator Eugene Forsey of Canada remarked that "in Canada, the Government and the House of Commons cannot be at odds for more than a few weeks at a time. If they differ on any matter of importance, then, promptly, there is either a new government or a new House of Commons."[6] However, the two branches have distinct roles, and in certain instances can come into conflict with each other. For example, in June 2021, the Speaker of the House of Commons directed a member of the public service to comply with an order of the House of Commons to share certain documents with the Commons, and the public servant refused to do so. The federal government announced that it would challenge the Speaker's ruling in the Federal Court,[7] but dropped the lawsuit in August when Parliament was dissolved for a federal election.[8]
The Danish government relies on the confidence of the parliament, Folketinget, to stay in power. If there is a successful motion of no confidence against the government, it collapses and either a new government is formed or new elections are called. The executive branch thus relies on the legislative branch.
The current French Fifth Republic provides an example of the fusion of powers from a country that does not follow the Westminster system. Rather France follows a model known alternatively as a semi-presidential system or 'mixed presidential-parliamentary' system, which exists somewhere between parliamentary democracies and presidential democracies.
Israel has a Westminster-derived parliamentary system, in which the Government is generally made up of members of the Knesset, Israel's parliament. It is legally possible in Israel to appoint ministers who are not members of Knesset, but that is usually not done. By law, the Prime Minister and Deputy Prime Minister must be members of Knesset.[9]
The parliamentary system in Sweden has since its new constitution in 1974 instituted a fusion of powers whereby the principle of "popular sovereignty" serves as the guiding light of principle of government and forms the first line of the constitution.[10]
The United Kingdom is generally considered the country with the strongest fusion of powers. Until 2005, the Lord Chancellor was a full fusion of all branches, being speaker in the House of Lords, a government minister heading the Lord Chancellor's Department, and head of the judiciary.