European Union Enlargement

When Ireland joined the European Economic Community (EEC) in 1973 it marked the beginning of a profound shift in the country’s development. What followed was a social and economic transformation that opened Irish trade to new markets, expanded educational and employment opportunities, and enabled significant investment in infrastructure and public services through European funding. 

While there are clear financial benefits to EU membership, each candidate country must also meet strict economic criteria to ensure stability across the Union. Most importantly, candidates must demonstrate a sustained commitment to the EU’s core values of human dignity, freedom, democracy, equality, the rule of law and human rights, as set out in Article 2 of the Treaty on European Union. The rule of law is central to the accession process and is assessed from the earliest stages and throughout negotiations, ensuring that laws are applied fairly, institutions function effectively, and citizens’ rights are protected.

There have been seven enlargements since the six founding members established the EEC in 1957, and each one has helped spread more stability, peace and prosperity across Europe. Today, the European Union comprises 27 Member States, with several candidate countries currently progressing through the accession process.

Ireland is a strong supporter of enlargement, opening embassies in key candidate countries like Serbia, Bosnia and Herzegovina and Moldova as part of the Global Ireland programme, and is expected to play a key role in advancing accession negotiations during its EU Council Presidency in 2026. 

EU Enlargement

EU enlargement policy highlights

Global Ireland

Enlargement as a priority

Enlargement is a key objective of the European Commission’s Global Europe priority for 2024-2029. This priority responds to dramatic changes the world has seen in recent years such as Russia’s illegal invasion of Ukraine, the war in Gaza and the rise of authoritarian leaders. It aims to strengthen the EU’s role in the world by building partnerships, supporting stable neighbours, protecting economic security, and improving international cooperation.

• Enlargement supports the Global Europe priority by:
• Expanding the EU’s geopolitical reach by bringing more countries aligned with EU values into the Union.
• Stabilising neighbouring regions by encouraging reforms in democracy, rule of law, and governance.
• Strengthening Europe’s security by creating a more unified and resilient political space.
• Boosting economic resilience with a larger single market, stronger supply chains, and deeper regional integration.
• Enabling joint action on global challenges, including energy security, climate policy, and migration.
• Increasing the EU’s influence globally by having more Member States speaking with a common voice in multilateral forums.

Global Europe priority

History of enlargement

Joining the European Union

Any European country can apply to join the EU, provided it meets membership requirements known as the Copenhagen criteria.

One of the most important of these is a strong rule of law. This means that laws are applied fairly, courts operate independently, governments are accountable, and fundamental rights are protected. These principles reflect the core values on which the European Union is built, including respect for human dignity, freedom, democracy, equality and human rights. Countries seeking to join the EU must demonstrate a genuine commitment to these values and show that they are embedded in their laws and institutions.

Candidate countries must also demonstrate stable democratic institutions, tackle corruption, protect minority rights and ensure freedom of the media. Progress is carefully monitored by the European Commission through regular reports. If reforms stall or standards slip, negotiations can slow or pause until progress resumes.

Here’s how the Accession Process unfolds:

• Application submitted: A European country formally applies for EU membership under Article 49 of the Treaty on European Union.
• Candidate status granted: The EU assesses whether the country respects EU values and is committed to meeting the accession criteria before granting candidate status.
• Screening of EU laws (the acquis): The European Commission reviews how far the candidate aligns with the 35 chapters of EU law and identifies reforms needed for compliance.
• Negotiation chapters opened: Each policy chapter, such as justice, environment, or competition, is opened individually, setting specific benchmarks the candidate must meet.
• Reforms and implementation: The candidate must reform its institutions, strengthen the rule of law, improve its market economy, and adopt EU rules in all policy areas.
• Regular monitoring and annual reports: The Commission tracks progress closely. Meeting benchmarks allows chapters to continue, while failure to progress can halt or slow negotiations.
• Closure of negotiation chapters: Once the EU determines that reforms are complete and laws are implemented, chapters can be provisionally closed.
• Accession Treaty signed: When all chapters are closed, the candidate signs an Accession Treaty, which must be ratified by all EU Member States and the candidate country.
• Full membership: After ratification, the country officially joins the EU and gains all rights and responsibilities of membership. 

Joining the European Union

Conditions for membership

Rule of law

EU values explained in a minute

Ireland’s path to membership

Ireland’s decision to join the EEC in 1973 is often framed as an economic milestone, but it also marked a major step towards completing the country’s independence. Even after formally leaving the British Commonwealth in 1949, Ireland remained economically tied to the United Kingdom. Throughout the 1950s and 1960s, the bulk of Irish exports were agricultural goods destined for British markets, leaving Ireland deeply vulnerable to decisions made in London.

Without access to wider European markets, it was almost impossible for Ireland to chart its own economic destiny. During the 1960s, successive Irish governments began modernising the economy and reducing reliance on Britain. Decades of protectionist policies were gradually dismantled, and Ireland opened itself to foreign competition in preparation for eventual EEC membership.

However, Ireland could not fully break from its deep‑rooted economic dependence on Britain without joining the EEC, and it could not join the EEC unless the UK did. Driven by economic decline at home and the evident success of the EEC, the UK applied for membership in the summer of 1961, and Ireland submitted its own application within days. After a two‑year wait, the UK’s application was vetoed in 1963 by France under President Charles de Gaulle, preventing Ireland’s application from moving forward. The UK applied again in 1967, but de Gaulle once more blocked the bid, arguing that Britain was not yet committed to European integration. As a result, Ireland’s second application was abandoned.

The path to membership finally opened in 1969 when President de Gaulle resigned, removing the main obstacle to enlargement. The Six Member States soon signalled their readiness to begin negotiations. Formal talks began on 30 June 1970, with detailed, face‑to‑face negotiations between Ireland and the European Commission starting in September that year. A referendum on membership took place on 10 May 1972, and an overwhelming 83% of Irish voters endorsed joining. Ireland officially became a member of the EEC on 1 January 1973, alongside the UK and Denmark.

Timeline to EEC Membership:

• 1961 - UK applies to join the EEC. Ireland submits its application days later.
• 1963 - France vetoes the UK’s application, forcing Ireland’s parallel application to be abandoned.
• 1967 – The UK reapplies and Ireland follows. France again vetoes the UK application, halting Ireland’s bid.
• 1969 - President de Gaulle resigns and the six EEC states signal readiness to reopen enlargement.
• 1970 - Formal accession negotiations begin on 30 June. Detailed bilateral talks start in September.
• 10 May 1972 - Ireland votes 83% Yes in a referendum on joining the European Communities.
• 1 January 1973 - Ireland, the UK, and Denmark officially become members of the EEC.

Ireland joining the European Community

History of Ireland in the EU

Key moments in Ireland's membership

Candidate countries

There are currently ten countries involved in the EU accession process. Nine have been granted official candidate status, while Kosovo is considered a potential candidate, having applied in December 2022.

Each year, the European Commission publishes its Enlargement Package, which sets out the EU’s approach to enlargement for the year. Its core component, the Communication on Enlargement, summarises progress made by candidate countries, identifies key challenges, and outlines the reforms still required. Alongside this, the package includes detailed country reports that assess reform progress over the previous year and provide recommendations on priority areas for further alignment.

Candidate countries in the Western Balkans follow a specific framework known as the Stabilisation and Association Process (SAP). To support their preparation for membership, the Commission has introduced a Growth Plan for the Western Balkans, aimed at strengthening political stability, economic reforms and investment in the region. The SAP countries are Albania, Bosnia and Herzegovina, Montenegro, North Macedonia, Serbia and potential candidate Kosovo. The remaining four countries outside the Western Balkans with candidate status are Georgia, Moldova, Ukraine and Türkiye. 

EU accession is merit‑based, meaning progress depends on the extent to which each country implements the required reforms. Candidates advance at different speeds based on their alignment with EU law across the 35 negotiation chapters organised into six thematic clusters. While the timeline for accession cannot be predicted with certainty, Montenegro is widely viewed by EU officials as the most advanced candidate, and Albania earned praise in the 2025–2026 enlargement reports for its significant progress. Moldova has also made substantial gains, and despite the ongoing war, Ukraine continues to advance reforms at a rapid pace.

EU 2025 Enlargement Package

EU and the Western Balkans

Growth Plan for the Western Balkans