Treaty of Lisbon — Treaty modifying the constitutional basis of the European Union, signed by all the States of the Union in Lisbon on 2007
The Treaty of Lisbon reformed EU governance by expanding qualified majority voting, creating permanent EU leadership roles, and granting member states an explicit right to leave the Union.
Key Facts
- Signed
- 13 December 2007
- Entered into force
- 1 December 2009
- Policy areas shifted to QMV
- At least 45 areas
- Irish first referendum result
- Rejected, June 2008
- Irish second referendum result
- Approved, October 2009
- Treaties amended
- Maastricht (TEU) and Treaty of Rome (TFEU)
By the Numbers
Location
Cause → Event → Consequence
Efforts to reform EU institutions began in 2001, producing the proposed Treaty establishing a Constitution for Europe. That constitution was rejected by French voters (55%) in May 2005 and Dutch voters (61%) in June 2005, forcing a rethink. Member states agreed instead to amend existing treaties rather than replace them, preserving many reforms originally envisaged in the failed constitution.
All EU member states signed the Treaty of Lisbon on 13 December 2007 in Lisbon, Portugal. The treaty amended the Maastricht Treaty and Treaty of Rome, expanding qualified majority voting to at least 45 policy areas, creating a permanent European Council President and a High Representative for Foreign Affairs, making the Charter of Fundamental Rights legally binding, and for the first time explicitly providing a procedure for member states to leave the EU.
After Ireland's initial rejection in June 2008 delayed ratification, a second Irish referendum in October 2009 approved the treaty following negotiated concessions. The treaty entered into force on 1 December 2009, restructuring EU decision-making, strengthening the European Parliament's legislative role, and establishing the legal framework that would later be used when the United Kingdom invoked Article 50 to leave the EU.
Political Outcome
Treaty entered into force 1 December 2009, reforming EU institutional structure including expanded qualified majority voting, new EU leadership roles, legally binding Charter of Fundamental Rights, and an explicit exit procedure for member states.
Council of Ministers dominant; unanimity required in many policy areas; no formal exit mechanism; Charter of Fundamental Rights non-binding
Bicameral legislature with stronger European Parliament; qualified majority voting in 45+ areas; permanent European Council President; legally binding Charter; explicit exit procedure