Matthew is a senior British civil servant and diplomat who most recently served as Permanent Secretary at the Home Office (2020-2025) and previously led the Department for International Development (2018-2020). He was the UK's Permanent Representative to the United Nations in New York (2015-2018) and held key roles in the Foreign Office, including Chief Operating Officer, EU Director, and Ambassador to Bosnia and Herzegovina. Earlier in his career, he served as Private Secretary to Prime Minister Tony Blair for foreign affairs and was involved in the Dayton peace talks. He was appointed a Knight Commander of the Order of St Michael and St George in 2023 for his contributions to diplomacy, development, and domestic policy.