Britain’s GCHQ spy agency chief will warn Western countries Tuesday of the "huge threat" from China seeking to exploit its tech dominance to control its own citizens and gain influence abroad.

Jeremy Fleming, the director of the cybersecurity agency, is set to tell a British defence studies body that the Chinese Communist Party views technologies such as satellite systems and digital currencies as a "tool to gain advantage".

In excerpts of his speech released late Monday, Fleming will use the annual "security lecture" at RUSI think tank to argue China could act in ways representing "a huge threat to us all".

He will urge the UK and its allies to respond urgently.

"At GCHQ it is our privilege and duty to see the sliding door moments of history. This feels like one of those moments," Fleming will say.

"Our future strategic technology advantage rests on what we as a community do next. I’m confident that together we can tilt that in our collective favour."

Fleming has headed the Government Communications Headquarters (GCHQ) since 2017 and has sought to bring the intelligence, cyber and security agency out of the shadows.

His comments come as China is in the process of launching its "digital yuan", raising fears that authoritarian countries could use digital currency to increase surveillance and control.

A centralized digital currency could "enable China to partially evade the sort of international sanctions currently being applied to (President Vladimir) Putin’s regime in Russia," Fleming is set to warn.

China has also launched a satellite navigation system, Beidou, as a rival to American GPS, compelling Chinese citizens to use it, Fleming will note.

"Many believe that China is building a powerful anti-satellite capability, with a doctrine of denying other nations access to space in the event of a conflict," he will add. 

"And there are fears the technology could be used to track individuals."

He will accuse China of seeking to gain "control of the markets" as well as "those in their sphere of influence and of their own citizens".

Fleming will also blame Beijing for creating "client economies and governments" by exporting technology to countries around the world, which risk "mortgaging the future" by buying in Chinese tech with "hidden costs".