UK Prime Minister Andy Burnham has raised the possibility of a new referendum on EU membership.

In 2016, Britain voted to leave the European Union.

Analysts say rejoining the bloc could boost Britain's sluggish economy, but the process would be fraught with challenges.

Where the debate stands now

Prime Minister Andy Burnham suggested this week that British voters may get the chance to overturn the divisive Brexit decision made a decade ago.

Burnham, who took office this summer, said in an interview on Wednesday that including a referendum on rejoining the EU in a future election manifesto was a possibility. The next UK general election is not expected before 2029. A prime minister can call an early election with parliamentary support, but Burnham, who succeeded Keir Starmer, has said he will not do so without a public vote.

In the interview, the prime minister said now is not the right time for a referendum, but Britain must examine all options for its relationship with the EU. "The position we are in is not ideal," he said. Asked whether he would include a "remain/leave" referendum option in a future election platform, Burnham replied: "Yes, anything is possible."

In the last general election, Starmer led the governing Labour Party to victory, ending 14 years of Conservative rule, while Burnham was serving as Mayor of Manchester. During his preparation to challenge Starmer for the party leadership, Burnham had promised not to reopen the Brexit debate. In another interview, Burnham said he wanted to "examine all options" for resetting UK-EU relations. Asked whether he wanted Britain to rejoin the EU, he said: "We can maintain the status quo. If the public thinks the current state is fine, that is certainly an option. We can also consider the customs union proposal put forward by former Chancellor George Osborne, or explore the single market, or simply choose full EU membership."

These interviews came after Burnham's speech at the Labour Party's annual conference on Tuesday. At the conference, he said plainly: "Brexit has not given us back control."

The 2016 Leave campaign promised to take back control of immigration policy, release more funding for the National Health Service (NHS), and strike trade deals with other countries around the world. Official UK statistics show that total exports of goods and services have grown significantly over the past decade, but disputes over immigration pressure and NHS funding gaps are sharper than ever.

Speaking at the party conference on Tuesday, Burnham said: "A UK-EU summit will be held later this year." "Unless we secure a long-term relationship with the EU, which remains our largest market, Britain will not find a clear path for the rest of this century. To be honest, the current situation is hardly satisfactory. The drawbacks of Brexit outweigh the benefits, and we need to restore higher levels of growth and prosperity."

A decade of Brexit in review

On June 23, 2016, the British public voted on whether to remain in the EU. The result that night shocked the world: voters chose to leave the bloc by 52% to 48%. After the result, the pound plummeted and London's FTSE 100 index fell sharply. Then-Prime Minister David Cameron, who had called the referendum and campaigned to remain, announced his resignation. Britain did not formally leave the EU until 2020. In the intervening years, Brexit remained a fiercely debated domestic issue. Remain supporters held ongoing protests, and some political parties put overturning the Brexit result in their election manifestos.

After cutting ties with its largest trading partner, the UK economy has largely failed to see the post-Brexit boost that was promised, and the pound has never returned to its pre-referendum level. The past decade has seen frequent changes of prime minister, with several of the seven leaders leaving office over their handling of Brexit and post-referendum economic problems.

James Smith, developed markets economist at ING Groep NV, said Burnham's remarks are politically significant, but securing real economic benefits would require substantive reform of the trade relationship, which could take years. "The prime minister has opened the door to full EU re-entry, but the reality is that he faces the same constraints as his predecessors," Smith wrote in an email. "The public may agree that Brexit has not worked well, but it is not clear that a majority supports rejoining. At the same time, given the recent turbulence in UK politics and the possibility of a Reform Party government in the future, how far the EU would be willing to make concessions in negotiations is completely unknown."

Smith noted that it took more than five years from the referendum to establishing a new economic and trade relationship with the EU. "Brexit has fallen down voters' list of political priorities, and I think it will take much longer for Britain to finalize and implement a completely new UK-EU relationship."

Steve Nolan, senior lecturer in economics at Liverpool John Moores University, told MarketWatch on Thursday that some estimates suggest UK GDP would be 5% to 8% higher today without the Brexit referendum. "Economists are not surprised by this. Classic trade models show that if you erect trade barriers with your nearest trading partner, there will inevitably be negative effects. So rejoining the EU would indeed bring clear benefits, but the road is bound to be bumpy."

He added that any new referendum would increase uncertainty and social unrest. "When Britain reapplies to join the EU, its negotiating leverage will be weakened, and it will likely have to accept many additional conditions, such as joining the eurozone and free movement of labor, which would create economic and political difficulties. The opportunity exists, but it will not come without a cost."

However, Nigel Green, chief executive of London-based financial advisory firm deVere Group, believes that although deeper ties with Europe could raise Britain's wealth level, it could also make it easier for capital to flow out of the UK.

"If Britain's relationship with its largest trading partner stabilizes, the pound could strengthen; the valuation gap for UK domestic stocks, which have traded at a discount for the past decade, may narrow." But he cautioned: "The door swings both ways. Many entrepreneurs and senior professionals have told deVere Group that they are considering leaving Britain to avoid high tax burdens."

"To reset UK-EU relations, Britain must also carry out domestic reforms: a competitive tax system, faster planning approvals, and stable policies that allow businesses to plan beyond the next budget. If both sets of reforms are implemented, Britain will become a magnet for European capital; if only one is done, Britain will simply become a place where capital finds it easier to leave."