The United Kingdom’s financial commitment to the AUKUS nuclear-powered submarine programme has risen to £12 billion, according to revised programme estimates contained in the Ministry of Defence’s 2025/26 annual report and accounts. This represents a 28% increase on the £9.4 billion estimate published at the time of the AUKUS partnership announcement in September 2021.
The National Audit Office, in its September 2026 examination of the MoD’s major projects, noted that the projected delivery of the first SSN-AUKUS class submarine to the Royal Navy had slipped from 2039 to 2042 — a three-year delay it characterised as carrying “strategic risk” given the planned retirement schedule of the current Astute class and the Royal Navy’s commitments under AUKUS to support Australian submarine capability development.
The Barrow Bottleneck
BAE Systems’ Barrow-in-Furness shipyard, the sole UK facility capable of building nuclear submarines, remains the primary schedule constraint. The shipyard is simultaneously building the final Astute-class boats and beginning preparatory work on SSN-AUKUS. A workforce expansion programme — targeting 5,000 additional skilled workers by 2030 — is running approximately 18 months behind schedule, according to BAE Systems’ own investor communications.
The apprenticeship pipeline serving Barrow is also under scrutiny. A National Skills Academy for Nuclear assessment published in 2026 found that the current pipeline, producing approximately 400 qualified nuclear submarine trades workers per year, would need to reach 700 per year by 2028 to meet AUKUS programme requirements. Current projections show it reaching approximately 520 by that date.
Parliamentary Oversight
The Public Accounts Committee launched a new inquiry into AUKUS programme governance in September 2026, following the cost and schedule disclosures. Committee chair Sir Geoffrey Clifton-Brown described the programme as “the largest single defence investment in UK history” and said the committee would examine whether oversight arrangements were “commensurate with the scale of the commitment.” The inquiry is expected to report in early 2027.