Britain is expected to announce a ban on the Chinese owned video-sharing app TikTok on government mobile phones imminently, bringing the UK inline with the US and European Commission and reflecting deteriorating relations with Beijing. The decision marks a sharp reverse from the UK’s previously relaxed position, but some critics and experts said Britain should also extend the ban to cover personal phones used by ministers and officials – and even consider a complete ban. An announcement is expected from the Cabinet Office potentially as soon as Thursday, sources said, and it follows an official review involving the government’s National Cyber Security Centre, an arm of GCHQ, and similar bans announced by the European Commission last month and the US in the past three weeks On Monday, prime minister, Rishi Sunak indicated he was considering whether to follow suit, saying he will take “whatever steps are necessary” to protect Britain’s security. The prime minister said the UK was “looking at what our allies are doing”, following initial reports that a ban would be recommended over the weekend. At least two cabinet ministers use TikTok. Michelle Donelan, the science and technology minister, and Grant Shapps, the energy security and net zero secretary, also has an account, on an app used by millions of young people and a string of celebrities and other influencers. Until recently, the UK had been relaxed about TikTok, with intelligence officials arguing that it was essentially for entertainment. Jeremy Fleming, the GCHQ boss, said last October said he would encourage young people to use TikTok, but said he would encourage them to “think about” how their personal data is used. Concerns appears to be centred on long-standing concerns about a 2017 national security law in China, which requires organisations and citizens to “support, assist and cooperate with the state intelligence work”. It has been cited in the past to justify bans on Huawei kit in UK and other 5G telecoms networks. TikTok said this week it would be “disappointed” if the UK banned the app on official phones. Referring to bans on official phones elsewhere it said: “Similar decisions … have been based on misplaced fears and seemingly driven by wider geopolitics, but we remain committed to working with the government to address any concerns.” Charles Parton, a China expert with 22 years of UK Foreign Office experience of working with the country, said he thought any ban should be extended to cover ministers and officials on their personal phones. “This all comes back to a lack of a security culture. In the days of the Soviet Union, there was general acknowledgment that some things had to be off limits. But China, although a bigger long-term threat to our security, economic prosperity, values and data, is not seen in the same light. It should be,” he added. This week the UK published its Integrated Review of defence and foreign policy, and marginally toughened its language on China, describing the country as posing an “epoch-defining challenge” – whilst declining to call it a threat as some, including Sunak’s predecessor Liz Truss, had sought. China’s embassy in London accused the UK of misunderstanding its intentions, arguing that “for all countries, China is an epoch-defining opportunity, not a challenge. China is committed to the path of peaceful development”. TikTok, ultimately owned by Chinese company ByteDance, is scrambling to convince lawmakers on both sides of the Atlantic that it can address concerns about data security and access to its recommendation algorithm, which curates what its more than 1 billion users see on the app.