Mobile phone users will be hit with signal blackouts lasting up to two days if ministers demand the removal of Huawei from the network too quickly, telecom chiefs warned yesterday.

Any tightening of restrictions on the Chinese giant could also lead to higher prices for customers and a delay in the rollout of faster 5G services, MPs were told.

Boris Johnson is expected to announce a U-turn over his decision to give Huawei the go-ahead to help build Britain’s 5G network.

Ministers are considering whether to axe the company amid fears the network could be used for spying by the Chinese state. A recent report said the security implications were ‘severe’ and that US sanctions on the firm may make its equipment less reliable and safe. 

It comes after the Daily Mail revealed a controversial dossier on Tuesday that accused China of trying to manipulate key Establishment figures in the UK to back Huawei.

But Vodafone and BT warned yesterday it would be ‘highly disruptive’ to mobile phone coverage if they were forced to remove Huawei from the network in the next three years.

Howard Watson, chief technology and information officer for BT Group, told MPs on the science and technology committee it would be ‘logistically impossible’ to do this in three years.

He said: ‘There would literally be blackouts for customers from 4G and 2G, as well as 5G, throughout the country. We would definitely recommend we do not go down that route.’

Mr Watson said engineers would have to take down the whole network, adding: ‘To take the whole network out would require multiple sites to be switched off at the same time, for at least a day, in some cases, for two days.’

For example, he said London was mainly served through equipment on rooftops. To rip out and replace the infrastructure would require closing streets and bringing in cranes.

He said it was not practical to do this in three years as is being discussed, saying it would require a minimum of five years and ideally seven.

In January, Britain set a cap to limit the use of Huawei equipment to 35 per cent by 2023.

Andrea Dona, head of networks for Vodafone UK, said: ‘If the current guidance were to be tightened further... we would need to spend in the order of billions to change our current infrastructure.’

He warned that a rapid U-turn would ‘undermine the resilience of the network’. Mr Dona said Vodafone would need a ‘realistic time-frame’ to minimise the impact of a ‘very challenging rip-and-replace’ programme.

Asked if the company could remove Huawei kit from phone masts within two years, he said: ‘They [consumers] would lose their signal, sometimes for a couple of days, depending how big and how intrusive the work to be carried out is.’

He said a five-year transition period would be the minimum required to avoid disruption.

Tory MPs are piling pressure on the Prime Minister to cut Huawei out of the network by the end of this Parliament in four years’ time.

Victor Zhang, chief representative of Huawei in the UK, told MPs that the company ‘doesn’t hide anything’.

He added that Huawei had created 26,000 job opportunities in Britain already and claimed the company’s involvement in the 5G network was ‘very critical for the UK’s economic recovery’.