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Reuters
Government ministers are calling for a "full and proper" investigation after high-level discussions about the UK using Huawei technology were leaked.
The government has approved the supply of equipment by the Chinese telecoms firm for the UK's new 5G data network despite warnings of a security risk.
It is believed the decision was taken at a meeting of the government's National Security Council on Tuesday.
One minister said leaking from the council was "simply not acceptable".
According to the BBC's political editor, Laura Kuenssberg, the senior minister said leaking from conversations was "extraordinary...the security council is the holy of holies".
The minister said there had to be a "full and proper leak enquiry", with those responsible losing their jobs if necessary.
And they added they had "huge concerns" over "getting into bed" with the telecoms giant.
Another minister said as many as six of them would be writing to Downing Street asking for a full investigation, and also for Number 10 to reconsider the merits of giving the Chinese firm any role.
There is no formal confirmation about the UK using Huawei technology in its 5G networks. Huawei already supplies equipment for the UK's existing networks.
Number 10 said a final decision would be made at the end of spring.
According to the Daily Telegraph, Huawei would be allowed to help build the "non-core" parts of the 5G network, such as antennas.
Huawei has denied that its work poses any risks of espionage or sabotage, or that it is controlled by the Chinese government.
But the US wants its allies in the "Five Eyes" intelligence grouping - the UK, Canada, Australia and New Zealand - to exclude the company.
Australia last year blocked its networks from using Huawei's 5G gear.
Four ministers 'against Huawei plan'
Prime Minister Theresa May chaired the weekly meeting of the government's National Security Council on Tuesday, where it is believed the decision was taken.
According to our political editor, a source said four cabinet ministers spoke against the idea, fearing that security could be compromised.
The source warned that allowing the firm to take part would be an error and was a "matter of the prime minister's judgement", and those arguing against the move had not yet given up.
Meanwhile, Conservative backbench MP Sir Nicholas Soames said the inquiry must be a criminal one and that the leak will "cause our friends and allies to wonder if we can be considered reliable - whoever is responsible should be dismissed [from] the Queen's service".
Separately, Westminster's powerful Intelligence and Security Committee is due to meet tomorrow and are expected to discuss the leak.
They were already due to launch a major investigation into China, including cyber security.
Leak from security council is different order
Separately from the decision itself - which has not yet been finalised - there is real upset over the fact the conversations leaked.
The current cabinet was memorably described as the "worst in British political history" for leaking by the man who, ironically, is meant to be in charge of discipline itself - the chief whip.
But for a leak to come from the security council is quite a different order.
As many as six ministers are therefore likely to write to Number 10 complaining and calling for a "full and proper" inquiry into who divulged the information.
What is 5G?
5G is the next (fifth) generation of mobile internet connectivity, promising much faster data download and upload speeds, wider coverage and more stable connections.
The world is going mobile and existing spectrum bands are becoming congested, leading to breakdowns, particularly when many people in one area are trying to access services at the same time.
5G is also much better at handling thousands of devices simultaneously, from phones to equipment sensors, video cameras to smart street lights.
Current 4G mobile networks can offer speeds of about 45mbps (megabits per second) on average and experts say 5G - which is starting to be introduced in the UK this year - could achieve browsing and downloads up to 20 times faster.