Unless you are the head of MI5, Sir Andrew Parker, or one of the Cabinet members permitted to attend the National Security Council (or you are following deliberations through a miniature webcam concealed within the fireplace clock positioned directly below the painting of Sir Robert Walpole), you will likely struggle to assess the level of security threat posed by permitting Huawei technology to operate parts of Britain’s “superfast” 5G future.

There are some stories that lobby journalists cannot investigate adequately because the information that informs a National Security Council recommendation cannot be shared. So, when Andrea Leadsom, the Business Secretary and National Security Council attendee, gives hints that are interpreted as implying that Huawei will not be barred when a decision is announced next week, who are we to gainsay her?  We may nevertheless – and it is no intended slight to Mrs Leadson or any of her colleagues – wonder whether having seen the evidence they can reasonably be expected to fully grasp not only what it contains but what considerations it might have missed.

There are, of course, two sets of evidence for the National Security Council to consider. One set was the dossier of technical information handed-over by the United States earlier this month which backed-up the American contention that permitting Huawei’s tech in the 5G network “would be nothing short of madness.” Sir Mark Sedwill, who combines being National Security Adviser with the role of Cabinet Secretary, allegedly “erupted” at the American delegation for persisting with this line.

From this we may surmise that Sir Mark is rather more impressed by the evidence from GCHQ which apparently amounts to recommending that British intelligence has got its Chinese counterparts licked. So long as Huawei’s role is “non-core” (antennas etc.) the threat is manageable.

This could be true, but how is anyone outside the Cheltenham doughnut (as GCHQ’s main office is lovingly described) and the National Cyber Security Centre in London to judge? Britain’s cryptographs and spooks really are good value for money if they remain one step ahead of the world’s most successful (by value) telecoms equipment provider, a company that spends annually over $15 billion on R&D – which is more than Apple, Microsoft or Intel.

Aside from the possibility that Huawei involvement is a risk that cannot be successfully manged, there is also the wider considerations of defying Donald Trump. The timing is hardly ideal, with a free trade agreement to be negotiated and the Trump administration already expressing its irritation about the UK’s incoming digital services tax which will slap American online platforms like Amazon, Google and Facebook with a 2 percent levy.

A more dangerous consequence would be if the UK found itself partially disconnected from the intelligence-sharing of the Five Eyes. None of the four other members of that spying alliance (Canada, United States, Australia and New Zealand) use Huawei. Australia – where fear of Chinese espionage and embeddedness has become a primary political issue – has been particularly clear that Huawei is banned.

This should not be treated just as a twenty-first century take on old racist fears about “Asiatics.” In April last year, Vodafone admitted to Bloomberg that there had been multiple security issues discovered in the software Huawei supplied between 2009 and 2011 which could have potentially given Huawei access to information communicated by millions of Vodafone users in Italy. This may, as claimed, have been an innocent oversight. But then Huawei was hardly going to say “fair cop, we left in those cyber-backdoors deliberately.”

The risk is that the UK becomes China’s cyber-backdoor into the Five Eyes. Even if that is not true, merely the possibility of such a prospect could persuade Britain’s espionage allies to be more guarded in what intelligence they share with us.

Yet, there is a reason that Boris Johnson’s government, for all its instinctive Atlanticism, is prepared to press ahead with Huawei regardless. The Conservative Party’s manifesto pledge was platitudinous – “we will ensure that Britain seizes the chance to be a world leader in the development of 5G, playing a key role in defining industry standards.” Johnson means business on this however, repeatedly emphasised that the country’s economic performance – particularly its ability to harness the potential of AI – depends on rapid roll-out of 5G. If that is the requirement, then only Huawei can meet it.

Huawei has been operating in Britain for eighteen years and has been part of the 3G and more recently 4G networks for most of that time. The Trojan horse is already inside the gates. Estimates vary as to how far behind trail the tech alternatives that could be supplied to Britain by Finland’s Nokia and Sweden’s Ericsson. A year or so, seems to be the average of informed views.

But given that major British telcos, Vodafone and BT, are already partly dependent on Huawei kit, removing it and starting again with an alternative supplier would add years, not months, of delay.

It would also dearly cost our beloved telcos. Guess who would be eventually paying that bill? So the calculation is whether to risk a direct and economic cost or a possible security/political cost. It is easier to apportion figures to the former.