The first time Liying* realised she was being watched, she was on her way home from an anti-Beijing protest outside the Chinese embassy in London in 2022. The sky was dark, and Liying – a student in her 20s from China – was walking with a fellow protester, megaphone in hand, when she noticed a stranger lurking behind them. The pair quickened their pace but the man, who looked Chinese, kept following. Ten minutes passed; then 20. Eventually, they ran into a nearby hospital and hid for more than half an hour. When they came out, he was gone. “Often at protests, there are middle-aged Chinese men standing a bit further apart, looking at us. They’re not joining, just examining,” says Liying, who has been followed a second time and received anonymous calls from China to her British number. “I get calls every day, from different numbers, saying they’re from an anti-scam team and asking me questions like whether I’m sending messages to people in China. I also got a call from the Chinese embassy asking about my health.” Liying is one of several students and recent graduates from China that the Guardian has spoken to who say they have been subjected to surveillance, harassment and other forms of intimidation by Chinese authorities for criticising the Chinese Communist party while on British soil. China is increasingly targeting people outside its borders in a tactic known as transnational repression, which aims to stifle debate or criticism. Steve Tsang, the director of the Soas China Institute, says Chinese student protesters in the UK have long been photographed and monitored, but the practice “may well” have increased with newer surveillance technology. Students say their families in China have also been threatened by local authorities, warning them to stop engaging in political activities overseas. Zhou*, a recent graduate in his 30s now working in the UK, joined protests and shared content on social media marking the 34th anniversary of the Tiananmen Square massacre last June. Soon after, his parents received a call from local police requesting they provide his British address and phone number, allegedly for Chinese residency registration purposes. Out of fear, Zhou stopped protesting for several months, and became depressed. In October, he logged on to WeChat, a Chinese social media platform, and posted for the first time in two years. A week later, his mother, who works in a government organisation, was summoned for a meeting by her boss, who informed her that Zhou was engaging in “sensitive” activities abroad. If she didn’t tell him to stop, their family’s jobs would be affected, her boss warned. “My mum was very upset, but I told her many students encountered a similar situation, and it was a normal thing,” Zhou says. “I’m constantly learning about the situation in China. In the past, I didn’t know anything about these red lines and what activities could be safe. I am still worried about my family’s safety. That’s the biggest issue.” Most of those interviewed by the Guardian who had participated in protests in the UK had never engaged in political activities before moving abroad and had been unaware of the risks. Fan* says his family in China were visited by the police and told their son had violated Chinese law when he spoke to journalists after attending a rally last year. He had criticised the government using his real name, and is too frightened to return home. In recent years, there have also been concerns about the impact of Chinese surveillance and influence on UK universities. Between 2021 and 2022, there were 151,690 students from China in the UK, making them the largest cohort of non-UK students. In March, Michelle Shipworth, an associate professor at University College London, told the Telegraph newspaper she had been banned from teaching a “provocative” China-related course to protect the university’s commercial interests. UCL said it was committed to safeguarding academic freedom of inquiry. Students say the fear of being surveilled by Chinese agents keeps many from engaging in politically sensitive discussions or activities and sows distrust within the community. One undergraduate student, Sun*, says he knows of peers who have been questioned by other Chinese students about whether they have attended anti-Beijing protests. He also showed the Guardian messages from a WeChat group consisting of Chinese students from his university reminding others to “express pro-China and pro-party views”. The president of City, University of London, Anthony Finkelstein, issued a statement last May acknowledging incidents of political pressure “from across the higher education sector”, including “actions undertaken by the governments of China, Russia, Iran and others”. Those who plan to keep speaking out, such as Fan are undaunted. He says the opportunity for protest and dissent in the UK has given him a political awakening. “I feel like I’ve entered a new world,” he says. “Before, I didn’t realise there were so many amazing people who have the same political opinions as me, who are willing to do something for our country.”