Prominent changes include more qualified majority voting in the Council of Ministers, increased involvement of the European Parliament in the legislative process through extended codecision with the Council of Ministers, eliminating the pillar system, preventing the provision in the Treaty of Nice (2001) reducing the number of commissioners, and the creation of a President of the European Council with a term of two and half years and a High Representative for Foreign Affairs to present a united position on EU policies. If ratified, the Treaty of Lisbon would also make the Union's human rights charter, the Charter of Fundamental Rights, legally binding.

The stated aim of the treaty is "to complete the process started by the Treaty of Amsterdam [1997] and by the Treaty of Nice with a view to enhancing the efficiency and democratic legitimacy of the Union and to improving the coherence of its action."[2] Opponents of the Treaty of Lisbon, such as the British think-tank Open Europe and former Danish MEP Jens-Peter Bonde, argue that it will centralise the EU,[3] and weaken democracy by moving power away from national electorates