LONDON Former British prime minister Rishi Sunak will take up senior advisory roles at U.S. companies Microsoft and Anthropic, an artificial intelligence startup, according to a U.K. government document. Sunak will be a part-time senior adviser at Microsoft, which will involve "providing high-level strategic perspectives on macro-economic and geopolitical trends," according to a U.K. public body which advises former senior officials on business appointments. The body advised Sunak, who is still