Prime Minister Boris Johnson has ordered Huawei equipment to be purged completely from Britain's 5G network by 2027, risking the ire of China by signalling the world's biggest telecoms equipment maker is no longer welcome in the West.
The seven-year lag will please British telecoms operators such as BT, Vodafone and Three, which had feared they would be forced to spend billions of pounds to rip out Huawei equipment much faster. But it will delay the roll-out of 5G.
The United States had long pushed Johnson to reverse a decision he made in January to grant Huawei a limited role in 5G.
London has also been dismayed by a crackdown in Hong Kong and the perception China did not tell the whole truth over the coronavirus.
Britain's National Security Council (NSC), chaired by Johnson, decided on Tuesday to ban the purchase of 5G components from the end of this year and to order the removal of all existing Huawei gear from the 5G network by 2027.
The cyber arm of Britain's GCHQ eavesdropping agency, the National Cyber Security Centre, told ministers it could no longer guarantee the stable supply of Huawei gear after the United States imposed new sanctions on chip technology.
Telecoms companies will also be told to stop using Huawei in fixed-line fibre broadband within the next two years.
"This has not been an easy decision, but it is the right one for the UK telecoms networks, for our national security and our economy, both now and indeed in the long run," Britain's Digital, Culture, Media and Sport Secretary Oliver Dowden told parliament.
"By the time of the next election, we will have implemented in law, an irreversible path for the complete removal of Huawei equipment from our 5G networks."
The US is worried that 5G dominance is a milestone towards Chinese technological supremacy that could define the geopolitics of the 21st century.
Huawei said Britain's "disappointing" decision to ban the use of its equipment in its 5G networks was "bad news for anyone in the UK with a mobile phone" and threatened to put the country into the digital slow lane.
It urged the government to reconsider.
"We remain confident that the new US restrictions would not have affected the resilience or security of the products we supply to the UK," a spokesman said.
After Australia first recognised the destructive power of 5G if hijacked by a hostile state, the West has become steadily more worried about Huawei.
The West is trying to create a group of rivals to Huawei to build 5G networks. Other large-scale telecoms equipment suppliers are Sweden's Ericsson and Finland's Nokia .
Trump has repeatedly asked London to ban Huawei which Washington calls an agent of the Chinese Communist state - an argument that has support in Johnson's Conservative Party.
Huawei denies it spies for China and has said the US wants to frustrate its growth because no US company could offer the same range of technology at a competitive price.