British Prime Minister Andy Burnham said he was open to calls for a formal apology for Britain's historical role in slavery, ​before attending next week's Commonwealth summit at which he is likely ‌to face demands for financial reparations. Writing in the Guardian newspaper, Burnham said Britain was "offering a structured dialogue with those affected by the transatlantic slave trade", in which at ​least 12.5 million Africans were abducted and sold into slavery. "Listening to ​calls for a formal apology on behalf of the British ⁠state will form an important part of this process, and I am ​open to them," he added. But Burnham rejected calls for financial reparations, writing: "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." From the 15th to the 19th century, millions of Africans ​were sold into slavery by European traders, with Britain transporting an estimated 3.2 million ‌people ⁠across the Atlantic, according to the Transatlantic Slave Trade Database. Ahead of the Commonwealth Heads of Government Meeting in Antigua and Barbuda next week, King Charles, who is touring the Caribbean, said it was "only right that we should ​acknowledge the great suffering ​and injustices of ⁠the past". Caribbean leaders are expected to press demands for reparations, which they have often framed in terms of ​debt relief, development finance, education, healthcare and climate resilience. Burnham ​also wrote ⁠in the Guardian that he wanted to "launch a new drive on debt", including by helping more vulnerable countries "repay over a longer time period and with better ⁠rates". Read more: King Charles' sorrow over slavery faces test as reparations movement gains ground Antigua ​and Barbuda Prime Minister Gaston Browne welcomed Burnham's ​comments and proposals for practical assistance, though he added in a Facebook post: "The Caribbean's longstanding ​position on reparatory justice remains unchanged."