The United Kingdom’s Prime Minister Andy Burnham has said his country is open to apologising for Britain’s role in the transatlantic slave trade but ruled out reparations, which campaigners have for years called for.

Burnham wrote in an opinion article in The Guardian on Friday that Britain would also work on debt restructuring for the poorest countries, marking an historic turn in London’s stance.

The move comes ahead of a four-day summit starting Sunday of the 50-plus Commonwealth nations formerly colonised by Britain. The UK’s King Charles, who arrived in the Caribbean last week, is hosting the leaders in St John’s, the capital of Antigua and Barbuda.

“I want to express my sorrow and regret for the pain and suffering of so many millions of people, and to recognise the way it still shapes our world today,” Burnham wrote, in what amounted to a personal apology.

Caribbean nations that have more forcefully demanded reparations in recent years said they expect more from Britain, while opposition Conservative Party leader Kemi Badenoch has criticised Burnham’s move as “navel-gazing”.

Here’s what we know:

What was Britain’s role in slavery?

Transatlantic slavery lasted between the 16th and 19th centuries and saw some 12 million enslaved Africans torn from their homes and forcibly transported on ships to the Americas with the help of local warlords. Enslaved people were sold on plantations and as domestic workers, and their labour produced goods that built wealth in Europe.

Britain and Portugal accounted for about 70 percent of all Africans exported to the Americas, while France, Spain and the Netherlands also traded in significant numbers of enslaved people. Britain alone transported 3.1 million Africans to British colonies in the Caribbean, the Americas and other countries, according to its national archives. Only 2.7 million arrived, as many perished in treacherous sea journeys.

British abolitionists began campaigning against slavery in 1787, particularly in cities like Manchester. In 1807, Parliament passed the Slave Trade Act, essentially banning new enslavement. More than three decades later, in 1834, Britain banned slavery in its entirety, although the practice continued for several years.

Amid calls for accountability in 2006, then-Prime Minister Tony Blair expressed “deep sorrow” for Britain’s role in the slave trade, but fell short of apologising or speaking about reparations.

Why now?

Burnham’s apology came during Britain’s Black History Month and as the Commonwealth is meeting in Antigua and Barbuda.

In his article, the British prime minister said London wants to keep diplomatic and trade ties with its Commonwealth allies.

“In an increasingly divided and dangerous world, our family of nations in the Commonwealth is vital to our interests,” he wrote, adding that Britain “can seize opportunities for trade and economic collaboration”.

Britain will allow the most vulnerable countries to repay their debts over a longer period, he added, with former Chancellor of the Exchequer Gordon Brown, who spearheaded the UK’s 1991 initiative to reduce debt for poorer countries, leading the charge.

What is the debate regarding apologies and reparations?

Since 2013, the Caribbean Community and Common Market (CARICOM) has called on Western countries involved to acknowledge their role and institute monetary reparations for slavery.

In recent years, those calls have grown louder, led by Barbados Prime Minister Mia Mottley.

Ghana, where around 10-15 percent of enslaved people were transferred from, has also played a major role and pushed a historic resolution at the United Nations in March that saw 123 countries vote to declare trafficking of enslaved Africans the gravest crime against humanity. All European nations abstained while the United States, Israel and Argentina voted against the measure.

Campaigners argue that there is a legal and moral case for financial payment and debt cancellations for the centuries of damage caused by enslavement. Those damages, they say, are evident in the structural inequalities that continue to plague countries where human capital was stolen from and those in the Caribbean that faced genocides after Europeans arrived.

They also point to the loss of lives, the erasure of cultures, the looting of artefacts in the colonial era that followed, and ongoing economic disparities and development challenges that see those nations struggle to access international financial institutions.

In June, Mottley announced a 19-point manifesto at a conference in Ghana, as Caribbean and African countries increasingly align to more strongly push their case. It called for a “full and formal apology”, monetary compensation from nations, but also institutions, including corporations and churches. It also called for technology transfer, education and healthcare funding, debt relief and economic development. The plan revised an earlier CARICOM 10-point plan.

“We live in a world today where people call out people for everything, for misogyny, for sexual assault, for all kinds of behaviour. But yet we have not found the moral courage to state unanimously across humanity that this grave crime against humanity that persisted for centuries ought to be declared so by all,” Mottley said at the conference.

Why are European nations not keen on reparations?

European nations, including Britain, argue that those crimes were committed long ago and that, as such, their people should not pay for them. Some also point to the role of local African chiefs who worked with the Europeans to kidnap and enslave people.

“I do not think that British people today can be held liable for historical wrongs, however heinous, that happened in a different age under different laws and in which they played no personal part,” Burnham wrote in The Guardian.

Instead, he said, the UK was “offering a structured dialogue” with those affected and debt restructuring.

France recognised slavery as a crime against humanity in 2001. In May, French President Emmanuel Macron said Paris should look into reparations, but did not make clear proposals.

In 2022, the Netherlands apologised for its role.

The Church of England, whose clergy also owned enslaved people, set up a fund of 100 million British pounds ($134mn) to cater to affected communities and to conduct further research into slavery’s legacies.

What are the reactions?

In a statement, Saint Lucia’s Prime Minister Philip J Pierre, who currently chairs CARICOM, said the organisation rejects the argument that Britain of today cannot be held responsible for slavery.

“Reparatory justice has never been about individual guilt. It is about the responsibility of states and institutions — and that responsibility does not expire with the passing of generations,” he said. Without repair, PM Burnham’s apology was “incomplete”, he added.

Ghanaian President John Dramani Mahama said he welcomed Burnham’s statement with “caution” and reiterated the need for a formal apology, targeted investments in several sectors, and an international commitment to “dismantle systemic racism and Afrophobia”.

Denis O’Brien, founder of the advocacy group The Repair Campaign, also said London “must stop obfuscating and give a full and formal apology now”.

The UK’s opposition Conservative Party leader Badenoch kicked against the move entirely in a post on X, and asked whether the descendants of African rulers involved would also be asked for reparations.

“There is no reason British taxpayers today should be held financially responsible for things that happened generations before any of us were born,” she said.

“Labour are already spending too much on Britain’s welfare state, now is not the time for Andy Burnham to be providing global welfare.”

Meanwhile, Bell Ribeiro-Addy, chair of the All-Party Parliamentary Group (APPG) for Afrikan Reparations, which endorses compensation, welcomed Burnham’s steps but said action was still “lacking”.