Theresa May has today been accused of showing 'very poor judgement' and risking the special relationship with the US by allowing Huawei to help build Britain's new 5G network.

The Prime Minister has defied security warnings from her own ministers, Donald Trump's White House and the CIA not to give the Chinese telecoms giant access because of its alleged links to President Xi's global spy network.

In a chorus of criticism at the decision, senior Tory backbencher Iain Duncan Smith said today: 'It puts special relationship under strain. I consider her [the PM's] judgement on this to be very poor. I would call a reconsideration of decision given nature of the risks it implies'.

Chairman of the Commons Defence Select Committee, Dr Julian Lewis, also warned Huawei 'intimately linked with the Chinese government' and its 'deeply hostile' intelligence services.

But Cabinet minister David Lidington htoday defended Huawei's potential involvement, insisting the company was privately run and not linked to the ruling Communist Party.

The decision threatens to divide the UK and US, who are suspicious of the firm, and risk sharing information between their secret services.

Rob Joyce, US Homeland Security Adviser, told a cyber-security conference in Scotland today: 'We're not going to - in the US - have Huawei in our most sensitive networks.'

And Trump's Secretary of State Mike Pompeo said in February: 'If a country adopts [Huawei] and puts it in some of their critical information systems, we won’t be able to share information with them, we won’t be able to work alongside them. We won’t even be able to co-locate American resources, an American embassy, an American military outpost'.

Theresa May has defied security warnings from senior Government ministers, Donald Trump's White House and the CIA not to allow controversial Chinese telecoms giant Huawei to help build Britain's new 5G network. Iain Duncan Smith says that she must reconsider

The National Security Council, which is chaired by the Prime Minister, yesterday gave the green light to give Huawei limited access to help construct sections of the network such as antennas and non-essential infrastructure.

Defending the move, Mr Lidington said today that 'legally speaking it is a private company not a government-owned company', but also added that no decision had been officially made.

He said the Department for Digital, Culture, Media and Sport had commissioned a wide-ranging review on the issues and was 'giving stronger priority to security across the entire telecommunication sector'.

What will Huawei be allowed to supply? 5G mobile connectivity promises much faster downloading speeds as existing 4G networks become clogged with an increased number of mobile users increasing watching video and streaming live footage on their devices. Current networks offer speeds of about 45Mbps (megabits per second), but 5G downloads could be up to 20 times faster, experts say. Information which has emerged today suggests controversial Chinese firm Huawei will be allowed to supply 'non-core' elements of the new network, such as the 'multiple output' antennae networks will use to boost signal strength and capacity. These are also expected to be smaller transmitters than the current, stand-alone, masts companies currently use. However, it is suggested the firm will not be involved in 'core parts' of the networks, such as the technology which checks device IDs and routes data. Advertisement

But Home Secretary Sajid Javid, Foreign Secretary Jeremy Hunt, Defence Secretary Gavin Williamson, International Trade Secretary Liam Fox and International Development Secretary Penny Mordaunt are all believed to have voiced concern over the decision.

The Prime Minister has had repeated warnings from senior British and American intelligence officials and the international community of the risks posed by allowing such access to the Chinese company.

The US has banned Huawei from its government networks and put pressure on other countries included in the Five Eyes intelligence agreement – the UK, Australia, New Zealand and Canada – to follow suit.

Meng Wanzhou, Huawei's chief financial officer and daughter of its founder, Ren Zhengfei, was arrested in Canada in December at the request of the US on charges of bank and wire fraud in violation of US sanctions against Iran.

She denies any wrongdoing and her father said the arrest was 'politically motivated'.

Today experts also appeared to split on the decision.

Ciaran Martin, the chief executive of the UK's National Cyber Security Centre – part of GCHQ – has previously stated that he was 'confident' the UK can manage the risk posed by Huawei.

Huawei, run by CEO Richard Yu (pictured), have been accused of aiding Chinese espionage

Speaking at the Cyber UK conference in Glasgow, he said today: 'I'm not going to shirk the current debate around telecommunications and 5G.

'To repeat what I've said on numerous occasions, as have ministers, as has Jeremy Fleming (GCHQ director) and others, there's a lot more to 5G security than just whether particular companies get particular contracts.

'There's a whole framework of improvement we need to make. I think you're looking at the united Five Eyes panel - a real show of unity, the strongest showing of public unity the Five Eyes have ever shown'.

What is Huawei's involvement in 5G and why is it controversial? The Chinese telecoms giant has got ahead of rivals by rapidly developing key parts of the 5G infrastructure and making it attractive to markets across the world with competitive prices. 'Huawei is considered months ahead of competition and restricting its involvement could be damaging to the UK's ambition to be among Europe's 5G pacesetters,' said Kester Mann, from CCS Insight. 'Already, all four network operators have signalled that they will launch commercial 5G services before the end of 2019. 'Cutting out the market leader would inevitably lead to higher costs of deployment which could ultimately be passed on to consumers.' EE owner BT - which confirmed last year that it had removed Huawei equipment from key areas of its 4G network - said: 'We're aware of the reports around a Government decision on Huawei's involvement in 5G networks. 'We haven't been directly notified of any detail as yet, and we will continue to liaise with the NCSC (National Cyber Security Centre) and UK Government to understand the latest decisions around the usage of Huawei for 5G networks.' Vodafone said: 'We do not have any Huawei equipment in our core network in the UK. We look forward to seeing the report.' Advertisement

But Rob Joyce, US Homeland Security Adviser, told the conference: 'The one thing we're very united on is there's a threat here. There are nations who do intend to come at our critical infrastructure and pose a threat.

'With that understanding all of us are pretty fairly certain that we're not going to use technologies that pose a threat in those most sensitive networks.

'We're not going to - in the US - have Huawei in our most sensitive networks. What I see playing out here is a discussion amongst all of us about the realities of where do you define sensitive networks and where does that start and end?'

But Chancellor Philip Hammond said the question of cost had to come into it.

He said: 'Where our security experts tell us that there are ways in which we can maintain security - whether that be in networks or installation - that avoid the most economically costly outcomes then we should look very carefully at those options'.

Australia and New Zealand have blocked Huawei from supplying equipment for its 5G mobile network.

Alex Younger, head of MI6, has previously warned that Britain needs to decide how 'comfortable' it is with Chinese-owned companies having involvement in its telecoms infrastructure.

Chinese companies are required to co-operate with the state's intelligence agencies, a principle that has raised significant concerns in the West. Huawei denies having any ties to the Chinese government.

Members of the Five Eyes intelligence alliance are to share a stage in the UK for the first time as the Huawei row raged today.

UK, US, Canada, Australia and New Zealand representatives will meet at the National Cyber Security Centre (NCSC) annual conference CYBERUK in Glasgow on Wednesday.

They will discuss their experiences and how they work together to defend against shared cyber security threats during a public session at the Scottish Event Campus.

It is the first time the five members of the alliance have done so in the UK.

The CIA has accused Huawei of being funded by Chinese state security. They say the technologies giant have received funds from China's National Security Commission, the People's Liberation Army and a third branch of the Chinese state intelligence network

'Five Eyes' will not use Huawei in sensitive tech networks, US official says None of the Five Eyes intelligence sharing nations will use technology from countries that pose a threat, such as Huawei and China in their 'sensitive' telecoms networks, a senior U.S. official said on Wednesday. A British security source said earlier on Wednesday that Britain would allow Huawei access to non-core parts of the 5G network, but block it from all core parts of the system. That puts it at odds with the United States which has told allies not to use the firm, fearing it could be a vehicle for Chinese spy operations. Rob Joyce, a senior official from the U.S. National Security Agency, said the Five Eyes group - made up of the United States, Britain, Canada, New Zealand and Australia - would not use technology from countries which posed a threat to critical national infrastructure. 'We are not going in the U.S. to have Huawei in our most sensitive networks,' Joyce told a conference in Scotland. 'What I see playing out here is a discussion amongst all of us about the realities of where do you define sensitive networks, where does that start and end. 'You will see us united and linked that those most sensitive networks ... won't have those technologies from those countries that pose a threat to us whether it's China and Huawei or others.' Advertisement

Digital Minister Margot James tried to dampen down reports that the Prime Minister has given the go-ahead to controversial Chinese firm Huawei getting involved in the UK 5G network.

She wrote in a tweet: 'In spite of cabinet leaks to the contrary, final decision yet to be made on managing threats to telecoms infrastructure.'

Ms James directed her followers to an interview with national Centre for Cyber security chief Ciaran Martin on the BBC Today programme this morning.

A Government spokesman refused to comment on whether any decision had been made but said the review would conclude 'in due course'.

He said: 'National Security Council discussions are confidential.

'Decisions from those meetings are made and announced at the appropriate time through the established processes.

'The security and resilience of the UK's telecoms networks is of paramount importance.

'As part of our plans to provide world-class digital connectivity, including 5G, we have conducted an evidence-based review of the supply chain to ensure a diverse and secure supply base, now and into the future.

'This is a thorough review into a complex area and will report with its conclusions in due course.'

Liam Byrne MP, Labour's Shadow digital minister, said immediate clarity was needed over the conflicting reports on the Government's decision on Huawei.

He said: 'Our digital networks already lag well behind the world's best, yet the Government continues to dither over Huawei. We need clarity on the risks and costs of a decision either way and we need it now.

'We're at a fork in the road. If the Government thinks Huawei threatens our security, it needs to explain why and what it plans to do about it.

'If it bans Huawei, telecoms companies are clear that 5G will be delayed for years and cost billions of pounds more.

'If that's the Government's choice then we need immediate clarity on what their plan B is to give us the 5G network our future prosperity demands.'

However Huawei, based in Dongguan city, Guangdong Province, China, pictured, insist they are independent of influence from the government

EXPLAINED: THE EVOLUTION OF MOBILE BROADBAND UP TO 5G The evolution of the G system started in 1980 with the invention of the mobile phone which allowed for analogue data to be transmitted via phone calls. Digital came into play in 1991 with 2G and SMS and MMS capabilities were launched. Since then, the capabilities and carrying capacity for the mobile network has increased massively. More data can be transferred from one point to another via the mobile network quicker than ever. 5G is expected to be 100 times faster than the currently used 4G. Whilst the jump from 3G to 4G was most beneficial for mobile browsing and working, the step to 5G will be so fast they become almost real-time. That means mobile operations will be just as fast as office-based internet connections. Potential uses for 5g include: Simultaneous translation of several languages in a party conference call

Self-driving cars can stream movies, music and navigation information from the cloud

A full length 8GB film can be downloaded in six seconds. 5G is expected to be so quick and efficient it is possible it could start the end of wired connections. By the end of 2020, industry estimates claim 50 billion devices will be connected to 5G. The evolution of from 1G to 5G. The predicted speed of 5G is more than 1Gbps - 1,000 times greater than the existing speed of 4G and could be implemented in laptops of the future Advertisement

'Cyber attacks do not respect international boundaries and many of the threats and vulnerabilities we face are shared around the globe.

'Each nation has sovereignty to defend itself as it sees best fit but it's vital that we work closely with our allies to make the world as safe as possible.'

Members appearing from Five Eyes are Mr Martin, Rob Joyce, from the US National Security Agency, Scott Jones, head of the Canadian Centre for Cyber Security, Scott McLeod, of Australia's Assure and Enable, and Jan Thornborough, of New Zealand's National Cyber Security Centre.

Specialists from across government, industry and law enforcement will attend the two-day summit.

It will include speeches from GCHQ director Jeremy Fleming and Cabinet Office Minister David Lidington.

The theme of CYBERUK 2019 is to develop good cyber security for the public and help to make the technology they buy more secure.

Around 2,500 security experts are expected to attend the conference.

Foreign Secretary Jeremy Hunt said: 'The UK is one of the leading cyber powers in the world - but this is a global threat that needs a global response.

'That's why we are working closely with our allies across the globe to deter and tackle cyber threats, share information and respond in a coordinated way to impose a price on malicious cyber activity.

'I am delighted to see 2,500 cyber security experts at CYBERUK in Glasgow, working to make cyberspace free, open, peaceful and secure.'