Britain’s top spy has sounded the alarm over a sharp rise in foreign espionage and sabotage attempts, revealing that MI5 recently disrupted a major Chinese plot targeting the UK’s national security.
Speaking with rare candor, MI5 Director General Sir Ken McCallum shared his frustration after a critical espionage case collapsed — even as his agency continues to face an unprecedented wave of global threats.
A Week of High-Stakes Security Drama
In what he described as a “challenging week,” Sir Ken confirmed that MI5 thwarted a Chinese-led plot in the last seven days alone.
He said it was one of many examples of growing aggression from hostile states, warning that foreign activity targeting Britain has risen by 35 percent over the past year.
The spymaster’s comments came amid heated political debate over whether Prime Minister Sir Keir Starmer’s government has been too soft on China.
In his annual national security speech, Sir Ken urged the government to “make the UK a hard target,” adding firmly, “We need to up our game.”
Frustration Over a Collapsed Espionage Case
Sir Ken broke from MI5 tradition by publicly addressing his disappointment over the collapse of the espionage case involving two men — Chris Cash, 30, and Chris Berry, 33 — who were accused of passing sensitive information to Beijing.
“Of course, I am frustrated when opportunities to prosecute national security threats are not followed through,” he admitted.
But he also emphasized that his team had successfully disrupted the activity, describing their actions as a “strong intervention in the interests of the UK’s safety.”
While the case was dropped after government officials declined to formally label China as an “enemy state,” Sir Ken defended his team’s work, saying they had “every reason to feel proud” of their success in detection and disruption.
“I Will Never Back Off from Confronting Threats”
Speaking from MI5 headquarters at Thames House, Sir Ken declared that his agency remains undeterred.
“I am MI5, born and bred,” he said. “I will never back off from confronting threats to the UK, wherever they come from.”
He stressed that the UK must defend itself more resolutely than ever, warning that the world is now in a “new era” of overlapping crises and complex dangers.
“We can’t rely solely on investigating and disruption,” he cautioned.
“We need to make sure our adversaries think twice before acting against us.”
Inside the “New Era” of Security Threats
Sir Ken described 2025 as one of the most turbulent periods MI5 has ever faced.
“We are contending with more threats, and more kinds of threats, than at any other time in modern history,” he said.
According to him, state threats are escalating sharply.
In the past year alone, MI5 has launched investigations into 35 percent more individuals linked to foreign intelligence activities.
These range from espionage and cyber infiltration to more aggressive tactics like surveillance, sabotage, and even physical violence on British soil.
“My teams are now uncovering attempts at arson and physical attacks commissioned by foreign agents — the kind of behavior we used to see only in terrorism cases,” Sir Ken revealed.
Iran, Terrorism, and Global Networks
While China poses a growing challenge, the MI5 chief also warned that Iran-backed groups have been linked to over 20 potentially lethal plots in the UK over the past year.
Meanwhile, terrorism remains a constant threat.
Since 2020, MI5 has disrupted 19 late-stage terror plots and intervened in hundreds of developing ones.
Sir Ken said his agency is currently handling “near record volumes” of terrorism investigations — describing it as the biggest operational shift since 9/11.
He added that Al Qaeda and Islamic State are becoming more ambitious once again, targeting vulnerable young people through what he called “the squalid corners of the internet where poisonous ideologies thrive.”
China’s Role and Political Fallout
When asked directly whether China represents a national security threat, Sir Ken didn’t hesitate.
“Do Chinese state actors present a threat to the UK? Of course they do — every single day,” he replied.
However, he refused to criticize Matt Collins, the Deputy National Security Adviser, whose decision not to label China a formal threat led to the collapse of the Cash and Berry case.
Sir Ken described Collins as “a man of high integrity and a professional of considerable quality.”
He declined to give a specific number of Chinese agents operating in Britain, but noted that the threat extends far beyond “classic embassy-based spies in the Le Carré mould.”
Instead, he explained, Chinese state actors use many sophisticated methods to collect valuable information across all sectors of British society — from Parliament to universities to critical infrastructure.
A Call to Strengthen Britain’s Defenses
Concluding his speech, Sir Ken made a direct appeal to policymakers: “There are choices to make — about where to draw the lines and what balances to strike.”
He warned that Britain cannot afford complacency as the world becomes more dangerous and unpredictable.
“In this new era,” he said, “we must ensure that the UK remains a place where our adversaries hesitate — where they know we are ready to act.”