The Mirror has apologised after it mistakenly used a picture of the wrong person to illustrate a story about the chancellor, Kwasi Kwarteng, on its website. Condemning the “terrible error”, which occurred on the first day of Black History Month, the publication said: “This morning a picture in a story about Kwasi Kwarteng was wrongly captioned on the Mirror website. This was a terrible error and we apologise to Mr Kwarteng and all our readers.” The apology came after Kwarteng tweeted a screenshot of an online story about the mini-budget, featuring a picture of Bernard Mensah, the president of international for Bank of America. The photograph was incorrectly captioned with the words: “Kwasi Kwarteng said he had to do ‘something different’ with mini-budget.” “That isn’t me… @DailyMirror” wrote the chancellor on Saturday morning in a tweet published just before 10am. Pledging to “redouble our efforts” to fight racism, the statement, released more than an hour after Kwarteng pointed out the mistake, added: “The Mirror has a long history of working against racism and we will redouble our efforts on this.” Among those to condemn the error was Ben Obese-Jecty, the chair of the Hornsey and Wood Green Conservatives. He said: “Good to see the Daily Mirror kicking off its coverage of Black History Month with this they-all-look-the-same-don’t-they clanger. “You’d think, given the coverage he’s received this week, that most people in the press would know what Kwasi Kwarteng looked like …” Kwarteng became Britain’s first black chancellor when he took up the role last month. The Guardian has contacted the Treasury for comment. The Bank of America declined to comment.