Richard Rose is Director of the Centre for the Study of Public Policy at the University of Strathclyde and Visiting Fellow at the Robert Schuman Centre of the European University Institute Florence. Read chapter 13 of How Referendums Challenge European Democracy: Brexit and Beyond– free until 2nd September 2020.

In taking back all controls from the EU, Boris Johnson’s government has also taken full responsibility for what happens beyond Brexit.  However, to paraphrase John Donne, no island is an island to itself. Even if Downing Street tries to blame all problems on Brussels or CV-19, many people will blame these costs on the government that got Brexit done. If British opinion polls start showing that a big majority regret leaving the European Union, what would it now take for the United Kingdom to become a member of the EU once again? For reasons that I set out in my new book, How Referendums Challenge European Democracy: Brexit and Beyond, the short answer is: Up to ten years.

First of all, the EU and its member states would need to be in visibly better economic and political shape than Britain. Secondly, the rosy scenario promised by Brexiters would be seen as a mirage. Thirdly, the largest Opposition party, Labour, would need to fight and win the 2024 British general election with a manifesto pledge to undo the damage done by Brexit. Such a positive but vague phrasing would leave open possibilities ranging from becoming a full member once again to getting Brexit right, that is, negotiating a new political agreement that gives Britain substantial benefits and obligations of a member state but without any of its political advantages.

If a British government showed it wanted to improve its relationship with the EU, the default position is that the UK would have to make a membership application under Article 49 of the Treaty on European Union. In other words, the UK would no longer have its opt out from the eurozone or a major financial rebate, as it did before withdrawal. An alternative is that the EU would consider an innovative form of associate membership that conferred economic benefits and costs without political rights. If Franco-German relations were going well, they might welcome Britain as a trading partner but not as a political partner in the making of EU policies.

Whatever agreement might be reached would not only require the approval of all EU member states but also of the British Parliament. The new Labour leader Keir Starmer is in a strong position to offer the party’s left-wing anti-EU faction the alternative of back me or invite the party’s fifth straight election defeat. As a forensic lawyer and Labour’s spokesperson on Europe before becoming leader, he has a better grasp of the details of UK-EU relations than Prime Minister Boris Johnson. If Labour was a minority government it could get a parliamentary majority for a new deal with Brussels from other pro-EU parties in the Commons.  Hardcore defenders of Brexit would be a small fraction of MPs after a chastening Conservative defeat.

The critical question for a pro-EU government is whether to put to a referendum whatever agreement it might reach. Given precedents, it would be difficult for a government to avoid a referendum if membership was negotiated. If associate membership were negotiated, the government could avoid the risk of rejection by a referendum. It would also be a fitting Alice and Wonderland outcome in which all could have prizes. Britain’s Eurosceptics would be safe from having an EU flag flying over their town hall; the City and industrial England would reap economic benefits; and ordinary Britons could sigh with relief about getting rid of the nuisances introduced to holiday travel and ties if the government got Brexit undone.