GCHQ has introduced a blueprint for a national cyber defence capability amid increased threats from adversaries.

Anne Keast-Butler, director of GCHQ, the UK’s intelligence, cyber and security agency, has delivered the first annual lecture at Bletchley Park. Her speech marked the 80th anniversary of the UKUSA intelligence agreement, which later evolved into the Five Eyes security alliance between the UK, US, Australia, Canada and New Zealand.

“It’s rare for any head of an intelligence agency to speak in public, but I’m doing so to you today because we are at a moment of consequence – where the actions we take and the partnerships we build are ever more critical given the threats we face,” said Keast-Butler at the start of her lecture.

She emphasised the importance of international partnerships for increasing resilience and harnessing technology for good amid a “narrowing window for the UK and allies to stay ahead”.

She warned about the increasingly brazen behaviour from adversaries with...