A decade after the United Kingdom voted to leave the European Union, public and scholarly interest remains predominantly focused on what the decision ultimately meant for Britain. However, Brexit has also profoundly altered the political dynamics on the continent, specifically as regards the EU’s decision-making processes. While the formal institutional framework remained intact, the withdrawal of the Union’s second most populous nation fundamentally disrupted its internal equilibrium of power.

This systemic shift is primarily evident in the Council of the European Union, where member state ministers meet. 

First, voting power has shifted. The Lisbon Treaty’s so-called double-majority rule requires that 55% of member states representing at least 65% of the EU population agree to proposed piece of legislation. This sets the threshold for member states wanting to form a blocking minority relatively high. Consequently, smaller states must align with a populous partner to veto legislation. By removing a major demographic heavyweight, Brexit disproportionately enhanced the pivotal influence of the remaining large member states. Smaller nations now have fewer key allies to leverage. The jury is still out on whether Germany or Poland has emerged as the primary beneficiary of this recalculated voting weight. 

Second, alliances have changed. The loss of the UK severely impacted the “frugal” and Nordic states, which historically relied on British influence to champion fiscal discipline and protect non-Eurozone interests. In response, these nations are often clubbing together in informal coalitions, such as the “New Hanseatic League” and the “Frugal Four”. Nonetheless, these alliances lack the demographic weight to independently form a blocking minority. Conversely, despite predictions that Brexit would revitalize the Franco-German axis, Paris and Berlin have struggled to capitalize on their increased formal authority to project a unified strategic vision for the Union.

The departure of the UK triggered a quiet geopolitical transformation within the Council, irreversibly altering the arithmetic of European power. Today’s landscape of fragmented alliances and contested leadership is the clear legacy of a Union that, ten years after the referendum, is still searching for its new internal equilibrium.

Javier Arregui Moreno is a Professor in the Department of Political and Social Sciences, Pompeu Fabra University.

Note: The views expressed in this post are those of the authors, and not of the UCL European Institute, nor of UCL.