BT has become the first UK company to join Anthropic’s Project Glasswing, gaining access to the frontier AI model Claude Mythos Preview as it seeks to strengthen cyber defences across its networks and improve protection for customers, the telecoms group announced on Monday.

The move was unveiled by BT chief executive Allison Kirkby during the UK Government’s AI Adoption Summit, an event aimed at accelerating the use of artificial intelligence across the economy. Project Glasswing brings together operators of critical infrastructure to use advanced AI tools to identify vulnerabilities in systems and data before they can be exploited by cyber criminals.

BT said participation in the programme would enhance its ability to defend critical national infrastructure and respond to increasingly sophisticated cyber threats. The company stated that it currently blocks around four million cyber attacks across its networks every day, highlighting the scale of activity targeting telecoms infrastructure.

In remarks delivered at the summit, Kirkby linked the deployment of AI to the resilience of the UK's digital infrastructure. “AI only works at scale when it is underpinned by future-ready networks that are secure, resilient, safe,” she said.

Kirkby said BT would continue working with government on the development of domestic artificial intelligence capabilities. She said the company wanted to support “the further development and deployment of sovereign British AI capability, so that the UK can be an AI maker and not just a taker”.

The announcement follows an open letter issued by telecoms regulator Ofcom in April 2026, which called on communications providers to assess security risks associated with frontier AI models and implement appropriate safeguards. The regulator highlighted concerns that hackers could use increasingly powerful AI systems to accelerate cyber attacks and develop more capable malicious software.

BT is seeking to apply the same technologies defensively. Jon James, chief executive of BT Business, said: “AI is changing cyber security fast, and businesses need trusted partners who can help them stay one step ahead. By joining Project Glasswing, BT will strengthen its own cyber security capability to protect our networks, our customers and the wider UK.”

The initiative builds on BT’s broader use of AI in cyber security services and follows a recently announced collaboration with Accenture to develop AI-powered cyber operations designed to detect and respond to threats at machine speed.

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