Pressure is growing inside the European Union to overhaul one of its most deeply entrenched rules, the unanimity requirement for important decisions, as member states grapple with how to prepare the bloc for its next wave of enlargement — and more broadly to adapt the decades old union for its future in a radically changed geopolitical environment.

What started out as an economic grouping gradually evolved into political cooperation, but after Russia’s full-scale invasion of Ukraine, the EU is now looking at how to protect its members against potential military threats. And that threat looks more real than ever after the Russian drone incursion into Polish airspace on September 10.

One of part of this response has been the unprecedented push from leading EU politicians for the bloc to invest into defence after the Nato summit in the Hague this summer increased defence spending pledges to 5% of GDP.

The other side of its geopolitical strategy is to advance enlargement into both the Western Balkans and the Eastern Neighbourhood countries — two areas where Russia has long struggled with the West for influence. In short, the EU is redefining itself as a geopolitical actor, with enlargement and deeper integration now viewed as means to project influence and strengthen Europe’s position in the world.

This comes as Europe’s neighbourhood has become increasingly unstable, not only with the threat posed by Russia, but also the war in the Middle East and the intensifying US-China rivalry. The unpredictably of the US, a crucial ally in normal times, has thrown Europe back on its own resources.

In this turbulent context, EU enlargement is the union’s most effective instrument for promoting stability and cohesion in its near neighbourhood. Yet, bringing new members into the bloc is no easy task, relying on both a commitment to reform from would-be members and unanimous agreement from existing member states to the main milestones of the accession process.

Six countries – Albania, Moldova, Montenegro, North Macedonia, Serbia and Ukraine – are at the negotiation stage or have been given the go ahead to start negotiations. Other countries from the Western Balkans also aspire to join the bloc.

As the EU looks toward a potential expansion to as many as 35 members, officials and diplomats have warned that the present requirement for unanimity on enlargement decisions could become unworkable, as discussed during a visit by Austrian and Slovenian officials to the Western Balkans last week.

A group of countries, led by Austria, Slovenia and Germany, are calling for the use of qualified majority voting in areas such as enlargement and foreign policy, arguing that the current unanimity rule allows single governments to hold the rest of the bloc hostage and slows EU decision-making at a time of mounting geopolitical strain.

The use of vetoes in particular by Hungary on issues concerning the war in Ukraine have also pushed the topic up the EU’s agenda. Alternatives are now being promoted by leading EU figures including European Council President Antonio Costa and European Commission President Ursula von der Leyen.

Unanimity rule

Under existing treaties, unanimity is required for decisions on foreign affairs, enlargement, taxation and the EU budget. The rule was designed to protect national sovereignty and ensure that every member, regardless of size, has a voice.

In practice, however, it has often slowed or blocked action on urgent matters such as sanctions against Russia.

Germany and some other member states argue that a more flexible voting system is essential for a larger, more assertive union. In 2023, a group of states launched a Group of Friends to foster qualified majority voting in the EU’s Common Foreign and Security Policy (CFSP).

“Against the backdrop of Russia’s war of aggression against Ukraine and the growing international challenges the EU is facing, the members of the Group are convinced that EU foreign policy needs adapted processes and procedures in order to strengthen the EU as a foreign policy actor,” said a statement from Germany’s Federal Foreign Office issued in May 2023, just over a year after Russia’s full-scale invasion of Ukraine. “Improved decision-making is also key to making the EU fit for the future.”

The following year, a “non-paper” was submitted to the European Council by Germany and Slovenia, proposing that member states approve intermediate steps in accession negotiations by qualified majority, while keeping unanimity for the formal opening and closing of talks.

As outlined by Slovenia’s Foreign Minister Tanja Fajon after a meeting with her then German counterpart Annalena Baerbock, the aim was to bring in a “more efficient enlargement process, proposing technical changes to the enlargement methodology to allow for qualified majority voting”.

Supporters say it would remove procedural bottlenecks that have repeatedly delayed enlargement decisions. Opponents, including Hungary, Greece and the Netherlands, warn that losing the veto would strip smaller countries of leverage in matters touching on national sovereignty.

Qualified majority voting is already used in some areas. A decision is approved under this system when at least 55% of EU member states — currently 15 out of 27 — vote in favour, and those countries together account for at least 65% of the bloc’s total population. This approach is known as the “double majority rule.”

Top level support

There have previously been unsuccessful reform efforts. Former Commission president Jean-Claude Juncker floated a similar proposal in 2018, suggesting that the so-called “passerelle clause” in EU treaties could allow qualified majority voting in foreign policy and taxation without formal treaty change.

“I believe the time has come to make use of the passerelle clause which allows us to move to qualified majority voting – the "lost treasure" clause of the Lisbon Treaty,” Juncker said in his 2018 State of the Union address. That idea stalled amid fears of backlash from smaller member states.

Before she left office, former German Chancellor Angela Merkel, together with French President Emmanuel Macron, also tried to call a vote in 2021 to end unanimity voting, but the motion was quickly rejected by the smaller countries.

However, it was clear that the debate had gained new traction when von der Leyen used her 2025 EU State of the Union address (video, transcript) address in September to urge member states that “it is time to break free from the shackles of unanimity”.

“I believe that we need to move to a qualified majority in some areas, for example in foreign policy,” she said.

Previously, in a speech at the Conference on the Future of Europe in 2022, von der Leyen had talked on the need to “go further” in reforming the bloc. Specifically, she said, “I have always argued that unanimity voting in some key areas simply no longer makes sense if we want to be able to move faster.”

Then at the informal European Council meeting in Copenhagen on October 1, Costa sought a consensus on the reform. According to a diplomatic source quoted by Euronews, Costa was “testing the water” with a proposal to allow enlargement clusters to be opened with the approval of a qualified majority. This was blocked, with Hungary’s Orbán among the most outspoken critics. Leaders are expected to revisit the issue at their next summit on October 23-24.

There is growing frustration with Hungary’s repeated use of its veto powers. Budapest has blocked multiple EU initiatives concerning Ukraine, including the start of formal accession talks and financial aid packages, citing concerns over the language rights of ethnic Hungarians in western Ukraine. Orbán spoke recently of rule-of-law concerns and what he described as Ukraine’s mistreatment of ethnic Hungarians as his reasons for blocking the talks.

EU foreign policy chief and former Estonian Prime Minister Kaja Kallas also said she has a Plan B in May to bypass Hungary’s veto, which involves starting accession negotiations with Ukraine in particular, but putting off the key votes to close the negotiations until after Hungarian Prime Minister Viktor Orban leaves office. The alternative is to invoke Article 7 “footdraggers” rule of the EU treaty and use it to strip Hungary of its voting rights.

The initial legal steps have already been taken, though they remain undisclosed, according to multiple EU sources cited by the European Pravda.

The essence of the plan, as reported by European Pravda, was to use processes that do not require unanimity of agreement by EU members to push Ukraine’s (and Moldova’s) EU accession process forward. In areas where unanimity is necessary for a final decision, the negotiations would be carried out in “parallel” by the other 26 members to reach agreements. Although the parallel negotiations would not be legally binding, they would carry significant political weight and effectively isolate Hungary.

Hungary, meanwhile, has positioned itself as the chief defender of the veto.

In the past, Hungary benefitted from the unanimity rule as Orban’s then allies in Warsaw, the former conservative government under the Law and Justice (PiS) party, often shielded Budapest from EU disciplinary action.

With Poland’s new pro-EU coalition now in power, Orbán lost a crucial ally, but has since found common cause with Slovakia’s Prime Minister Robert Fico. They may get another ally in Czechia, where Andrej Babiš’s ANO party is expected to form a new, largely eurosceptic government. This would maintain a bloc of Central European countries at odds with the rest of the union on some crucial issues.

Enlargement momentum

More broadly, the debate over voting reform is closely linked to renewed momentum for enlargement. Russia’s invasion of Ukraine has transformed the political calculus in Brussels, making enlargement not just a question of economic integration but one of security and influence.

Ukraine and Moldova were granted candidate status in 2022. Candidate status for Bosnia & Herzegovina and Georgia followed. The Western Balkans, long in waiting, are again being reassured that their path to the EU remains open. Albania, for example, has raced ahead in its accession process, and is now hopeful of entering the bloc by the end of decade along with neighbouring Montenegro.

Yet the slow pace of progress for others — North Macedonia has been a candidate for two decades, its path repeatedly blocked by bilateral disputes with Greece and Bulgaria — has fuelled scepticism across the region.

Indeed, it is not uncommon for certain EU member states to wield their positions as veto-holders to look to settle historic grievances and wrest concessions from aspiring members. As well as Hungary’s position on Ukraine, the prospect of more countries from the Western Balkans — a region with a history of bitter ethnic conflicts — joining the bloc raises the question of whether new members will take a similar stance in demanding concessions from those that are slower to join.

Leaving aside the tensions over the accession process itself, once this happens, it has become clear that admitting a large number of new members without reforming the decision-making system would make future paralysis almost inevitable. Despite the mounting frustration, rapid change is unlikely. Still, with enlargement back on the political agenda and the geopolitical environment hardening, top officials have made it clear that the discussion can no longer be postponed.