DEFENCE Secretary Gavin Williamson has revealed “grave” concerns over a Chinese firm providing a new mobile network in the UK — amid spying claims.

Huawei is one of a handful of firms which has developed the next generation of mobile internet, known as 5G.

But there are widespread concerns the technology would allow China to spy on private lives and hack companies at will in Britain.

Now Mr Williamson has said: “I have grave, very deep concerns about Huawei providing the 5G network in Britain. It’s something we’d have to look at very closely.

“We’ve got to look at what partners such as Australia and the US are doing in order to ensure they have the maximum security of that 5G network and we’ve got to recognise the fact, as has been recently exposed, the Chinese state does sometimes act in a malign way.”

His intervention, on a trip to Ukraine where tensions with Russia are at fever pitch, is the latest in a concerted push to prevent China dominating the new network.

Earlier this month, MI6 chief Alex Younger questioned Huawei in a rare public lecture.

The spy master, said: “We need to decide the extent to which we are going to be comfortable with Chinese ownership of these technologies and these platforms in an environment where some of our allies have taken a quite definite position.

“We need to have a conversation. It’s not wholly straightforward.”

Australia has blocked Huawei, which has repeatedly denied the allegations, from supplying equipment for its 5G.

And New Zealand has said it will consult before a final decision.

Foreign Secretary Jeremy Hunt last week directly accused China for the first time of hacking after cyber crooks seized trade secrets.

Mr Hunt blamed Beijing for attacks made by a shadowy group dubbed APT10.

IT experts said they had identified Chinese hackers at the heart of bids to steal tech from firms based in Europe, Asia and the US.

The campaign, dubbed Cloud Hopper, is said to have saved Chinese firms millions by copying more advanced Western products.

Experts from the National Cyber Security Centre will brief company bosses on how to ward off hack attacks in the New Year.

The Government has pointed the finger at other states for previous incidents. The 2017 WannaCry ransomware breach was blamed on North Korea and Russia’s GRU military intelligence service has been accused of other attacks.