Britain cannot respond effectively to major geopolitical crises, including Russian aggression and political instability in the United States, unless it rejoins the European Union, according to a paper published by the Institute for Public Policy Research. The influential thinktank, which is close to the Labour party, has become the latest organisation to call for the UK to re-enter the bloc.
The paper argues that formal sovereignty is meaningless if the country lacks the practical ability to act on it. «Sovereignty without the ability to act on it is not autonomy,» the institute states in its assessment, framing the case for re-entry around capability rather than sentiment.
The intervention comes as the debate over Britain's post-Brexit relationship with Brussels widens. Andy Burnham, the Mayor of Greater Manchester, has said he wants to examine all possible options for the UK's future ties with the EU, signalling that the question is no longer confined to the political fringe. The IPPR's contribution adds institutional weight to that shift, placing a respected research body alongside figures who are openly testing the boundaries of the current settlement.
At the centre of the argument is the claim that the UK's ability to project influence and coordinate responses to international shocks has been diminished. The paper points to two distinct pressures: Russian aggression, which has reshaped European security calculations, and political turmoil in the United States, which has introduced uncertainty into the transatlantic relationship. In both cases, the thinktank contends, London is better placed to protect its interests from inside the EU's decision-making structures than from outside them.
The timing of the intervention is significant. The Labour party, now in government, has consistently ruled out a return to the single market or customs union, preferring a narrower reset of the UK-EU relationship. The IPPR's paper pushes against that caution, suggesting that the scale of external threats demands a more fundamental rethinking. Because the institute is regarded as close to Labour, its conclusions are likely to be read as a signal that the parameters of the debate are being tested from within the party's own ecosystem rather than only from its critics.
The thinktank's intervention also reflects a broader pattern in British foreign policy commentary, in which the costs of Brexit are increasingly assessed through a security and diplomatic lens rather than a purely economic one. By linking EU membership to crisis management, the paper reframes re-entry as a practical instrument of statecraft. That framing may prove more durable than arguments centred on trade flows, because it speaks directly to voters' concerns about national resilience and influence in a volatile world.
Opponents of rejoining are likely to reject the premise. For critics, EU membership entails pooling decision-making authority and accepting rules set elsewhere, which they regard as a loss of the control that Brexit was meant to restore. The IPPR's response is embedded in its central formulation: that autonomy without the capacity to act is an illusion. The paper therefore sets up a contest over what sovereignty means in practice, not merely whether Britain should be inside or outside the bloc.
The immediate effect is to keep the question of Britain's European future alive in Westminster and beyond. With a government committed to a limited reset, the thinktank's paper does not change policy by itself. But it adds a prominent voice to a conversation that is moving from whether the UK should reconsider its relationship with the EU to how far that reconsideration should go.