Boris Johnson former aide Dominic Cummings claims China ‘stole’ UK state secrets — and Whitehall buried it

Boris Johnson’s former chief adviser Dominic Cummings has made explosive claims that China compromised Britain’s most secure data systems for years, stealing vast amounts of top-secret information — and that senior officials covered it up.

Driving the news
Cummings, one of the most influential figures in Johnson’s Downing Street, alleged that a breach of the UK government’s highest-level classified data network — known as the “Strap” system — allowed Beijing to harvest “extremely secret and extremely dangerous” information over a prolonged period.


He said he and Johnson were first informed of the breach in 2020, and that they were warned disclosing details could be a criminal offence. The stolen material, he claimed, included intelligence agency data, documents from the National Security Secretariat, and other highly sensitive state secrets.

“It was so bizarre that people in the room thought they must have misheard,” Cummings told The Times, describing the meeting where the breach was disclosed. “Vast amounts of data classified as extremely secret were compromised.”

Why it matters
If accurate, the breach represents one of the most significant national security failures in modern British history — potentially exposing intelligence operations, diplomatic strategies, and critical infrastructure vulnerabilities to a foreign power.

Cummings alleges that the Cabinet Office prioritised protecting relations with Beijing over confronting the breach publicly, arguing that “the British state has prioritised Chinese money over its own security for decades.” He claimed that even current ministers, including Prime Minister Keir Starmer, may be unaware of the full extent of the compromise.

The revelation comes amid deep political fallout from the collapse of a high-profile Chinese espionage prosecution. The Crown Prosecution Service (CPS) dropped charges against two men accused of spying for Beijing after the government declined to officially state that China was a “threat” to national security at the time of the alleged offences.

The big picture
What was stolen: The “Strap” system — the UK’s highest classification level — was reportedly compromised. This includes intelligence data, Cabinet Office secrets, and sensitive state material.

Duration of breach: According to Cummings, the network transferring the UK’s most sensitive data was infiltrated “for years.”

Official cover-up: Cummings claims senior officials warned those informed not to discuss the breach with the media, with some evidence deliberately “buried.”

Economic vs security priorities: He accuses successive governments of downplaying threats from China to protect trade and investment ties.

Political fallout: The allegations coincide with Starmer’s decision to publish witness statements linked to the collapsed spy trial — documents that could shed light on the government’s stance on Chinese espionage.

Bottom line: Cummings’ claims, if substantiated, point to a systemic failure of Britain’s national security apparatus and raise profound questions about how successive governments have balanced security risks against economic interests with China. They also put renewed pressure on Prime Minister Starmer to fully disclose the scale of Beijing’s infiltration and the British state’s response.