In 2025, the Office of Value for Money set out its definition for mega- projects—the government’s largest and most complex projects—and the government announced changes to how it manages mega-projects to help remove obstacles to delivery.34 The NAO found that Northern Powerhouse Rail has five of the six mega-project characteristics. These include: • having cross-cutting impacts that span multiple government departments; • delivery taking longer than 10 years and spanning multiple Parliaments; and • being very expensive, with whole life costs over £10 billion.35 30 C&AG’s Report, paras 11 and 2.7 31 Q 16 32 Q 26 33 C&AG’s Report, para 11 34 HMT, Value for Money study on the governance and budgeting arrangements for mega projects, 19 June 2025 35 C&AG’s Report, Figure 7 12