The Daily Mail has quoted unnamed senior sources as saying that Chinese-supported hackers may launch a so-called "cyber-9/11" attack on Britain.

The sources pointed to government ministers’ concerns about "a perfect storm" pertaining to diplomatic spats between Beijing and London over Hong Kong, Huawei, and the coronavirus that may finally result in a full-fledged hacking attack on the UK.

"Obviously this is part of our conversations. But at the same time, all risk must be looked at in the round. Huawei is a menace and not acting on it risks national security. Actions, however, have consequences and they cannot be discounted", one of the sources argued.

In the worst-case scenario of a cyber-attack, hackers may damage the UK's computer networks, which would lead to phone and power blackouts and bring hospitals and businesses to a standstill, according to the sources.

The remarks followed British Shadow Security Minister Conor McGinn on Saturday referring to "this time of heightened tensions", and urging the government to "be alert to the risk of cyber-attacks from hostile states and prepare accordingly".

He said that the country's "critical national infrastructure should be ready and able to repel any such attack on the UK". 

The sources' warning of a possible all-out cyber-attack comes after The Telegraph reported late last week that UK Prime Minister Boris Johnson is set to start excluding the use of the Chinese tech giant Huawei's technology in Britain's 5G network this year "in a major u-turn". In February, the government announced that the UK would, with conditions, allow Huawei to assist in building the 5G network in Britain.