Britain faces a 'moment of consequence' with growing threats from Vladimir Putin and China, the head of GCHQ will warn in her inaugural annual lecture today.

Spy chief Anne Keast-Butler will set out the dangers Russia poses, as the country is 'scaling up its daily hybrid activity against the UK' – with operatives 'relentlessly targeting critical infrastructure, democratic processes, supply chains and public trust'.

She will urge GCHQ to 'see around corners' in order to protect our national security, warning of a 'narrowing window for the UK and allies to stay ahead' due to the growth of China as a 'science and tech superpower'.

Ms Keast-Butler is also expected to emphasise the importance of Britain getting to grips with advancing AI technology.

To mark the 80th anniversary of the UK-US intelligence agreement, she will deliver the lecture at GCHQ's wartime home Bletchley Park, emphasising the importance of international partnerships at a time when the so-called 'Special Relationship' has never been under more strain.

Addressing academics, government officials and national security partners, she will warn Britain is in a 'new era of radical uncertainty, contested geopolitics and rapidly changing technology'.

She will talk about GCHQ's work in 'disrupting Russia's efforts to smuggle Western tech, fending off cyber attacks, and countering reckless sabotage and assassination attempts'.

Despite the war in Ukraine raging on, Ms Keast-Butler believes Putin is not making gains: 'As we remain steadfast in our support for Ukraine, Putin is going backwards on the battlefield'.

Her speech comes as a Russian warship has been patrolling waters off the Suffolk coastline for almost two months without intervention.

The Admiral Grigorovich has become a common sight near Galloper Wind Farm, in open defiance of Downing Street sanctions.

The Government previously announced British commandos had been granted authority to board sanction-busting vessels.

But days later ministers were forced to backtrack after officials discovered the Kremlin's tankers and cargo vessels are protected by anti-piracy laws.

The Ministry of Defence said: 'The Royal Navy has consistently monitored and tracked Russian military vessels operating near UK waters.'