The issue has moved back onto the British political agenda during the Labour Party's annual conference in Liverpool, which ended on Wednesday.
Prime Minister Andy Burnham said that Britain should examine its long-term options, including a customs union, a return to the EU single market or full European Union membership.
He said Brexit "has caused more harm than good."
The comments followed calls from London Mayor Sadiq Khan for the government to begin preparing the ground for eventual EU membership.
Former Labour Prime Minister Tony Blair has also argued that Britain should work toward rejoining a reformed EU within the next decade.
Any return, however, would require Britain to go through the EU accession procedure again, according to Przemysław Biskup, an analyst at the Polish Institute of International Affairs (PISM) and a lecturer at the Warsaw School of Economics (SGH).
"This would not be a re-accession, as some imagine," Biskup said. "Formally, it would be no different from Ukraine's accession process."
He said negotiations could be shorter because British law remains closely aligned with the EU's body of legislation after almost five decades of membership, but Britain could not assume that the special terms it accumulated before Brexit would be restored.
Those included the British rebate, which reduced the country's contribution to the EU budget, and opt-outs that allowed Britain to remain outside the euro currency and the Schengen passport-free travel area.
Under Article 49 of the Treaty on European Union, a British application would require the unanimous approval of all 27 EU member states and the consent of the European Parliament. The resulting accession treaty would also have to be ratified.
Małgorzata Kaczorowska of the University of Warsaw's Faculty of Political Science and International Studies said there was still no political consensus in Britain, including within Labour, on a return to full membership.
The divisions have been visible at the Liverpool conference. Labour Deputy Leader Lucy Powell has previously argued against going beyond the reset in relations with Brussels pursued by former Prime Minister Keir Starmer, while Unite trade union leader Sharon Graham has said politicians must respect the result of the 2016 Brexit referendum.
Public opinion has nevertheless moved. A YouGov survey published in June found that 55 percent of Britons supported rejoining the EU in principle. Support fell to 35 percent if Britain could not retain its former opt-outs.
Kaczorowska said closer economic integration with the EU, including greater access to the single market without full membership, could prove more politically realistic in the coming years.
Biskup also cautioned that EU governments would determine the terms of any future negotiations. Britain's former membership would give it experience of EU rules and institutions, but no automatic claim to its previous privileges.
Britons voted to leave the EU in June 2016. The United Kingdom formally left the bloc on January 31, 2020, and its post-Brexit transition period ended on December 31 that year. Relations have since been governed largely by the EU-UK Trade and Cooperation Agreement.
Russian interference in Brexit is believed to have played a significant role in the campaign, particularly through social media disinformation and support for the Leave campaign.
Reports indicate that Russian-backed accounts promoted Leave messages extensively, potentially influencing the narrow victory for Brexit.
Burnham on September 23 announced the creation of a new National Centre for Information Defence designed to tackle online disinformation.
(rt/gs)
Source: PAP, polskieradio.pl