Under fire...

On Wednesday, BT announced it was removing Huawei’s telecommunications equipment from its 4G cellular network, following a warning from the head of the MI6 foreign intelligence service that singled out the Chinese company as a potential security risk.

But Robert Hannigan, former head of the GCHQ intelligence agency that deals with cyber-security, yesterday warned of “hysteria” over Chinese technology.

“My worry is there is sort of a hysteria growing... we need a calmer approach,” he told BBC Radio 4’s Today programme.

British intelligence agencies have not “reported a backdoor or malicious intervention” by Huawei, and any official criticisms so far are of “incompetence rather than malice,” he added.

But he warned that 5G presented a different challenge given that more data is processed locally, making it harder to keep tabs on.