Andy Burnham has explicitly mentioned rejoining the EU as one option for Britain’s future relationship with Europe, alongside joining a customs union, returning to the Single Market or retaining the current arrangements.
The political ground has shifted. YouGov polling published on 8 October found that 52% would vote to rejoin in a new referendum, compared with 27% who would remain outside. Recent research also estimates that Brexit has left UK economic output 6 to 8% lower than it would otherwise have been. Russia, disrupted trade routes and Chinese economic competition have increased the value of European cooperation on defence, energy and industrial policy. France, Germany and Spain have publicly welcomed the possibility of Britain returning.
However, Britain could not simply reverse Brexit; it would reapply under Article 49 as a new candidate. Accession would require unanimous approval from EU governments, consent from the European Parliament, negotiations over EU law and ratification by every member state. A UK referendum would be politically likely, although not legally compulsory.
The Euro and Schengen are default obligations for new members, but neither would necessarily apply immediately. Britain would be expected to adopt the Euro after meeting the convergence criteria and join Schengen once its borders met the required standards. New opt-outs could theoretically be negotiated through the accession treaty. However, Britain’s former rebate and opt-outs expired when it left, and Emmanuel Macron has warned that Britain could not “pick and choose” between the EU’s freedoms. Only 35% of Britons support rejoining without the previous opt-outs.
The debate reflects the competing assumptions of liberalism, realism and the English School. Growing economic costs and shared security threats strengthen the liberal argument that Britain can achieve more through European institutions than it can alone. Yet any agreement will still depend on national interests: EU governments will determine the price of readmission, while Britain must decide how much regulatory autonomy it is prepared to surrender. The English School offers a possible middle ground. Britain could remain a sovereign state outside the EU while participating in a European international society built around shared rules, diplomacy and institutions. A customs union, regulatory agreements and deeper security cooperation may therefore be more realistic than an immediate application for full membership.