Found the article, it was Spain specifically that requires it https://www.theguardian.com/politics/2026/feb/13/dual-nationals-denied-entry-to-uk-british-passpor

Found the article, it was Spain specifically that requires it https://www.theguardian.com/politics/2026/feb/13/dual-nationals-denied-entry-to-uk-british-passport-border-control https://www.theguardian.com/politics/2026/feb/13/dual-nation...