Cosine, the British AI company selected by the UK Government as part of its Sovereign AI initiative, today announced that it has brought together a coalition of leading UK institutions to co-design Lumen Sovereign, which it describes as Britain’s first sovereign frontier AI model.
Founded in 2023 in London, Cosine is a British sovereign AI frontier lab developing advanced models and coding agents that top public benchmarks — purpose-built for defence, national security and regulated industries where foreign-built AI is off the table and assurance by design is non-negotiable.
Its platform can run entirely within a customer’s own infrastructure, with no external dependencies, delivering frontier AI that is developed, deployed and operated under full UK control.
Babcock International Group, BT, Lloyds Banking Group, LSEG, NatWest Group, PwC, Thales UK, BAE Systems, Leonardo UK, and Telefónica Tech UK&I are amongst the companies to have signed memoranda of understanding to participate in the model's design phase.
The coalition reflects the fact that many of the UK's largest institutions are increasingly seeing AI as a strategic dependency risk. Just as organisations have spent years reducing reliance on single energy suppliers or foreign-controlled communications infrastructure, a growing number of the UK's defence, financial and public sector institutions are reaching the same conclusion about AI.
