The constitution’s overarching aim is to streamline the process of making decisions in the new, 25-nation European Union, mainly by reducing the number of policies that can only be agreed by unanimity.

* An E.U. president will be chosen by national governments, for a maximum of five years. This replaces the current system of a rotating presidency, held for six months by each member state in turn. He or she will be, in effect, the head of the Council of Ministers, which some compare with a lower house of parliament for the E.U., made up of ministers from each national government, and holding key decision-making powers.

* An E.U. foreign minister will be chosen by national governments for five years, and will be supported by his own diplomatic service, another innovation. He or she will only be able to speak if E.U. countries have agreed on a common policy, but once they have agreed, he will be “asked to present the union’s position” at the United Nations.

* The European Parliament’s powers will grow, leading some to call it the European Union’s upper house of parliament. It will have powers over 95% of E.U. legislation, and the right to reject a proposed law after three readings.

* The Charter of Fundamental Rights, which is not new, has been dropped, wholesale, into the constitution.

* The constitution contains innovations that may come about in the future if all nations agree, such as the creation of a European prosecutor and a common defense policy among them.