At the European Council meeting in Laeken, EU leaders adopted the Laeken Declaration, arguing that upcoming enlargement made existing EU decision-making harder and that the Union needed clearer, more democratic institutions. The declaration set the political agenda for a formal reform process and paved the way for a new Convention to draft proposals.
The Convention on the Future of Europe began meeting to develop proposals for reforming the EU’s treaties and institutions. Its “Convention method” brought together representatives from member-state governments, national parliaments, the European Parliament, and the European Commission, aiming for more transparent treaty drafting than earlier closed negotiations.
After months of public debates and drafting, the Convention agreed on and submitted a draft Treaty establishing a Constitution for Europe. The draft tried to simplify the EU’s treaty structure and adjust institutions for a larger Union, reflecting concerns that unanimity voting and existing rules would be too slow after enlargement.
EU leaders agreed on the Constitutional Treaty at a European Council meeting, moving the project from drafting to formal signature and national ratification. This was a key transition from “proposal” to a treaty intended to replace and streamline parts of the EU’s existing legal framework.
Representatives of the EU member states signed the Treaty establishing a Constitution for Europe in Rome. Signature did not make it law; the treaty still required ratification by every member state under national rules (parliaments and, in some countries, referendums).
In a national referendum, French voters rejected the proposed EU constitution. Because the treaty required unanimous ratification by all member states, this “No” vote created an immediate blockage and forced EU leaders to reconsider how to pursue institutional reform.
A few days after France, Dutch voters also rejected the EU constitution in a consultative referendum. With two founding members voting “No,” the EU’s constitutional project effectively stalled, leading to a shift toward a less “constitutional” and more amending-style treaty.
On the EU’s 50th anniversary, leaders signed the Berlin Declaration, reaffirming shared values and signaling a renewed push to settle institutional reform before the 2009 European Parliament elections. It helped end the post-2005 “pause” by setting political momentum for a new treaty approach.
EU leaders agreed on a detailed mandate for an Intergovernmental Conference (IGC) to draft a “reform treaty” that would keep many substantive changes from the failed constitution, but present them as amendments to existing treaties. This decision launched the final negotiating phase that led directly to the Lisbon Treaty text.
EU leaders signed the Treaty of Lisbon in Portugal, choosing a treaty that amended existing EU treaties rather than replacing them with a single “constitution.” The Lisbon approach aimed to deliver institutional changes—such as more streamlined decision-making—while avoiding some politically sensitive constitutional symbolism.
Ireland held the EU’s only referendum on the Lisbon Treaty and voters rejected it. This prevented the treaty from entering into force as planned, because every member state had to ratify before the treaty could take effect.
After additional political assurances and renewed debate, Ireland held a second referendum and approved the Lisbon Treaty. This cleared the biggest remaining ratification obstacle and moved the treaty close to final approval across the EU.
After legal and political delays, the Czech Republic completed ratification and deposited its instrument with Italy (the treaty depositary). This was the last required step to complete ratification by all member states, triggering the treaty’s scheduled entry into force on the first day of the following month.
The Lisbon Treaty entered into force, completing the EU’s main round of institutional reform after the 2005 constitutional setback. Among its consequences, the EU Charter of Fundamental Rights gained binding legal status (by reference), reinforcing rights protections as part of the EU’s primary law and shaping how EU institutions and member states apply EU law.
Lisbon Treaty and Institutional Reform (2002-2010)