Due to the Federal Council's unique nature as a voluntary grand coalition of political opponents, its operation is subject to numerous constitutional conventions. Most notable is the principle of collegiality; that is, the Councillors are supposed not to publicly criticise one another, even though they are often political opponents. In effect, they are expected to publicly support all decisions of the Council, even against their own personal opinion or that of their political party. In the eye of many observers, this convention has become rather strained after the 2003 elections (see below).