Can Europe Govern Without Unanimity? The Battle Over the EU’s Veto

The European Union is often expected to act as a single political force when faced with international crises. Yet, when its Member States attempt to agree on certain foreign policy decisions, the Union can find itself constrained by a rule that gives every national government the power to withhold its consent. In an organisation of twenty-seven Member States, unanimity can protect national interests and ensure that decisions on sensitive matters command broad support. It can also make collective action difficult precisely when speed and coordination matter most.

This tension is not new, nor is it simply a question of whether European integration should proceed further. It concerns the institutional balance on which the Union was built: how can the EU act effectively while respecting the sovereignty of its Member States, particularly in areas where governments have deliberately retained close control over decision-making?

The debate has become especially significant in foreign and security policy, where disagreements between national governments can affect the adoption of common positions and restrictive measures. But unanimity is not confined to external action. It also applies in areas such as taxation, the accession of new Member States and certain decisions concerning the Union’s finances. The question, therefore, extends beyond foreign policy: is the EU’s existing system of vetoes a necessary safeguard of national sovereignty, or does it risk undermining the Union’s ability to fulfil its common objectives?

The answer cannot be reduced to a simple choice between unanimity and majority voting. The Treaties already establish a differentiated system of decision-making, while providing mechanisms through which some unanimity requirements can be reconsidered. Understanding those mechanisms is essential to assessing what reform is legally possible, what political obstacles remain and whether a more effective Union requires a fundamental revision of its constitutional framework.

Unanimity is the exception, but it matters where it applies

The Council of the European Union uses several voting procedures, including simple majority, qualified majority and unanimity. Qualified majority voting is the ordinary rule in many EU policy areas. Under the standard procedure, a proposal is adopted when at least 55% of Member States — currently 15 out of 27 — representing at least 65% of the EU population vote in favour. Unanimity, by contrast, requires every Member State to agree, although an abstention does not prevent a decision from being adopted. The applicable rules depend on the relevant Treaty provision. [1]

Unanimity is retained for matters that governments regard as particularly sensitive. These include significant parts of the Common Foreign and Security Policy (CFSP), EU enlargement, certain tax measures, the Union’s own resources and some decisions relating to social protection and justice and home affairs. The Treaties specify the areas in which the rule applies; it is not a general requirement for every decision taken by the Council. [1][2]

This distinction matters. It would be inaccurate to describe the EU as an organisation in which every government can veto every European decision. In much of the Union’s legislative work, Member States can be outvoted in the Council, with the European Parliament acting as co-legislator under the ordinary legislative procedure. In other fields, however, the Treaties preserve a more intergovernmental approach, giving national governments a direct means of preventing a decision to which they object.

There are reasons for that choice. Foreign policy can involve military commitments, national security assessments and relations with third countries, while taxation affects domestic economic policy and the distribution of public revenue. Governments may therefore consider it unacceptable to be bound by a decision opposed by their own representatives. Unanimity can also encourage negotiation and ensure that a common position reflects a wide range of national concerns.

Nevertheless, a requirement for every government to agree changes the incentives facing negotiators. A disagreement over one issue can prevent progress on another, and a government may have considerable leverage even when its position is not shared by most of its partners. The resulting difficulty is not that consensus is undesirable, but that the institutional requirement to achieve it can make agreement impossible.

The foreign policy dilemma: a common position, twenty-seven national interests

The Common Foreign and Security Policy illustrates the tension particularly clearly. Unlike many areas of EU law, CFSP remains governed by specific procedures that preserve a central role for Member States and generally require unanimity in the Council. The Treaties do provide for exceptions and particular circumstances in which qualified majority voting can be used, but these do not remove unanimity as the general rule for CFSP decisions. [3]

The practical consequence is that the EU’s ability to formulate a common external position can depend on whether all governments are prepared to accept it. Member States may agree on a broad objective while disagreeing about the timing, scope or political implications of a particular measure. Where unanimity is required, a single government can prevent the Council from adopting the decision, even if the other Member States support it.

This can be especially consequential when the Union is considering restrictive measures, diplomatic responses or other forms of collective action. The European Parliament’s 2023 report on the implementation of the Treaty passerelle clauses identified the use of national vetoes to block or delay foreign policy decisions as a concern and called for greater use of existing Treaty mechanisms to facilitate qualified majority voting in selected areas. The report also stressed that the passerelle clauses have limitations, including the political obstacle created by the requirement for unanimous approval to activate them. [4]

The institutional problem is therefore more complex than a simple contest between a majority and a minority. A veto may reflect a substantive disagreement about the policy itself, a concern about national interests or a broader dispute within the Union. It may also create pressure to link agreement on one question to concessions in another. The legal effect is clear when unanimity is required: without the necessary agreement, the Council cannot adopt the proposed decision. The motives behind a particular government’s position, however, must be assessed on the evidence rather than assumed.

For supporters of reform, this is a reason to expand qualified majority voting in carefully defined areas. They argue that a common foreign policy loses practical force if the Union cannot act when a broad majority of its members agree. Opponents of such a change raise a different concern: majority voting could oblige a Member State to accept a common position on a matter it considers fundamental, potentially weakening national democratic accountability and the willingness of governments to participate in common action.

Both concerns are relevant to the design of the system. A Union that cannot agree on a response may struggle to act collectively, but a Union that regularly imposes decisions on governments that consider them vital to their national interests may face political resistance to implementing those decisions. The institutional challenge is to find a procedure that allows the EU to act without treating national consent as irrelevant.

The Treaties already contain a possible way forward

The debate is sometimes framed as though the EU must choose between retaining the existing rules indefinitely and undertaking a complete revision of its founding Treaties. The legal position is more nuanced. The Treaties already contain so-called passerelle clauses, which allow certain decision-making rules to be changed without a formal Treaty amendment. Their purpose is to make the Union’s procedures more flexible while respecting conditions agreed by the Member States. [5]

The general passerelle clause in Article 48(7) of the Treaty on European Union provides two distinct possibilities. First, the European Council may authorise the Council to act by qualified majority in an area where the Treaties would otherwise require unanimity, subject to the conditions laid down in that provision. Second, it may authorise a move from a special legislative procedure to the ordinary legislative procedure, thereby increasing the European Parliament’s role in the relevant decision-making process. [5]

These are not interchangeable changes. Moving from unanimity to qualified majority affects how the Council reaches a decision. Moving to the ordinary legislative procedure also changes the role of the European Parliament. The passerelle clauses are therefore relevant not only to the speed of decision-making, but also to the institutional balance between Member States and the EU’s supranational institutions.

The general passerelle mechanism is subject to important safeguards. The European Council must act unanimously, the European Parliament must give its consent, and any national parliament may object within six months of the relevant notification. The general clause also cannot be used to extend the Union’s competences: it changes how the Union exercises powers conferred on it, not the scope of those powers. Furthermore, the general passerelle does not apply to decisions with military implications or those in the field of defence. Specific Treaty provisions may establish separate procedures for particular policy areas. [5][6]

A related provision, Article 31(3) TEU, allows the European Council to decide unanimously that the Council may act by qualified majority in additional cases within the CFSP, subject to the Treaty’s limits. This offers a more targeted route for changing voting rules in foreign policy without reopening every aspect of the Treaties. [6]

In principle, these provisions offer a route between institutional paralysis and comprehensive Treaty reform. They allow governments to consider a shift in voting rules while remaining within the constitutional framework they have already accepted. In practice, however, they expose the central difficulty of the debate: the transition away from unanimity itself requires a high degree of agreement.

The veto is therefore not simply a rule that can be removed by a majority of governments. In the general passerelle procedure, each government retains a decisive role at the point when the change is proposed. A government that opposes surrendering its future veto may be able to prevent the very reform intended to limit that veto. The legal mechanism exists, but its use depends on political willingness.

Why has the passerelle mechanism not resolved the debate?

The European Parliament’s 2023 report on the implementation of passerelle clauses noted that the general clauses had not been activated since the Lisbon Treaty entered into force in 2009. The report called on Member States to make use of the available mechanisms, particularly in selected areas of foreign policy, while also recognising that the requirement for unanimity in activating them remained a major obstacle. [4]

This helps explain why the debate continues. The difficulty is not solely a lack of legal instruments. It is also a disagreement about whether governments are prepared to change the conditions under which they exercise power within the Union.

For a government, retaining a veto can be understood as a guarantee that it will not be bound by a common decision on a sensitive matter without its consent. Giving up that guarantee may therefore be perceived as a constitutional and political decision, rather than a technical adjustment to the Council’s voting rules. The fact that a passerelle clause exists does not mean that the governments concerned will necessarily agree to use it.

At the same time, the existence of the clauses undermines the idea that Treaty reform is the only available route to greater flexibility. In policy areas covered by the relevant provisions, governments could choose to use the existing mechanisms rather than wait for a broader revision. That would not solve every problem associated with unanimity, but it could allow changes to be made in specific fields without renegotiating the entire institutional framework.

The question is therefore partly one of sequencing. Should the Member States first make fuller use of the flexibility already provided by the Treaties, or should they prioritise a more comprehensive reform that changes the rules at a deeper level? The two approaches are not necessarily mutually exclusive. The passerelle clauses can be considered as a limited, existing tool, while formal Treaty revision remains available for changes that cannot be achieved through them.

Would qualified majority voting solve the problem?

Moving to qualified majority voting would reduce the ability of one government to block a decision in areas where the change applied. It would not, however, guarantee that the Union would act quickly, consistently or ambitiously in every situation. Governments would still have to negotiate, build coalitions and reconcile different national priorities. A proposal might fail to obtain the necessary majority, and a decision adopted at European level would still depend on effective implementation.

Nor would qualified majority voting remove the need for democratic legitimacy. The Council is composed of representatives of national governments, while the European Parliament represents EU citizens directly. The balance between those institutions differs according to the applicable procedure. Any expansion of majority voting should therefore be assessed not only by reference to efficiency, but also in light of accountability, transparency and the consequences for Member States whose representatives oppose a decision.

There is also a distinction between changing the voting rule and changing the Union’s powers. The passerelle clauses can alter certain decision-making procedures, but they cannot confer new competences on the EU. If Member States want the Union to act in an area where it currently lacks the necessary legal authority, a different legal route may be required. [5]

A reform proposal should consequently identify the precise problem it seeks to address. If the obstacle is that a decision within an existing EU competence requires unanimity, a passerelle clause may offer a possible solution. If the obstacle is the absence of an EU competence, changing the voting threshold alone will not resolve it. If the concern relates to the legitimacy of a decision, institutional safeguards and the role of the European Parliament may be just as important as the voting rule itself.

The choice is not between an EU that acts and an EU that does not. It is about the conditions under which collective action is authorised, and how those conditions can preserve both the Union’s capacity to act and the political consent on which integration depends.

Reforming the rules without disregarding national sovereignty

Any sustainable reform must acknowledge why unanimity was retained in the first place. The EU is not a unitary state, and its Member States have not transferred all aspects of foreign policy, taxation or national security to the European level. Their governments remain accountable to domestic electorates and operate within different constitutional and political traditions. A system that ignores these realities would risk creating a gap between decisions taken at EU level and the willingness of national authorities to support them.

Yet sovereignty does not necessarily require unanimity in every field. Member States have already accepted qualified majority voting across large parts of EU decision-making, including through successive Treaty revisions. The history of European integration shows that the voting rules are not fixed once and for all; they are part of the institutional settlement negotiated by the Member States. [2]

The relevant question is where the balance should lie. One approach would be to retain unanimity in areas where governments consider national consent indispensable, while expanding qualified majority voting in more clearly defined fields where delays impose significant costs on the Union as a whole. Another would be to make greater use of the passerelle clauses already available, allowing carefully delimited changes before attempting a broader reform. Both approaches would require governments to agree on the scope of the change and on the safeguards that should accompany it.

Treaty revision remains a more comprehensive option. Article 48 TEU establishes procedures for amending the Treaties, but formal revision involves agreement among Member States and ratification in accordance with their respective constitutional requirements. It can therefore provide a route to deeper institutional change, while also presenting substantial political and procedural hurdles. [7]

There is no guarantee that reform would eliminate disagreements between national governments. Nor should the objective be to eliminate disagreement: in a political union of twenty-seven states, disagreement is inevitable and can be a legitimate expression of democratic pluralism. The aim would instead be to prevent a single government from blocking every decision in areas where the Member States have agreed that collective action should be possible by a different voting rule.

Conclusion: The veto is a constitutional choice, not an untouchable principle

The debate over unanimity goes to the heart of the European Union’s constitutional structure. The veto can protect national interests and preserve consent on decisions that governments regard as particularly sensitive. But when unanimity is required, it can also prevent the Union from adopting a common position even where most Member States support action. The tension is especially visible in foreign policy, although the same institutional question arises in other areas covered by the Treaties.

The existing legal framework already offers limited routes towards more flexible decision-making. The general passerelle clause in Article 48(7) TEU and the specific provision in Article 31(3) TEU demonstrate that the Treaties are not entirely rigid. Nevertheless, their safeguards and approval requirements mean that they cannot be treated as automatic solutions. The legal possibility of reform and the political willingness to undertake it are two separate questions.

Ultimately, the choice is not between national sovereignty and European integration as mutually exclusive principles. It is a question of how the Member States wish to exercise their sovereignty together, and in which areas they are prepared to accept that a common decision should not depend on the consent of every government. The future of EU decision-making will depend less on whether unanimity is defended or criticised in the abstract than on whether the Member States can agree on where the veto remains indispensable, where it has become an obstacle, and what safeguards should accompany any change.

For the European Parliament’s Committee on Constitutional Affairs, this is a fundamental institutional question: how can the Union preserve the legitimacy of decisions taken by its Member States while ensuring that its decision-making rules remain capable of responding to the challenges for which the Union was created?