A parliamentary researcher has been arrested on allegations of spying for China - ITV News Security Correspondent Rohit Kachroo has the latest
Oliver Dowden has said the UK must be "clear-eyed" about challenges posed by China, after a parliamentary researcher was arrested on suspicion of spying for Beijing.
The deputy prime minister told MPs it would be inappropriate to comment on the ongoing investigation, but insisted the government must be clear that China represents a "systemic challenge to the UK and our values".
He added the UK "must be able to look the Chinese in the eye and call out unacceptable behaviour directly".
On Monday, the detained parliamentary researcher protested their innocence in a letter released via their lawyers.
The researcher - who was not named in the statement by the law firm Birnberg Peirce - said he was "completely innocent", despite his arrest under the Official Secrets Act in March. His arrest was not disclosed until Sunday.
In a statement released by his lawyers, the man said: "I feel forced to respond to the media accusations that I am a 'Chinese spy'.
"It is wrong that I should be obliged to make any form of public comment on the misreporting that has taken place.
"However, given what has been reported, it is vital that it is known that I am completely innocent.
"I have spent my career to date trying to educate others about the challenge and threats presented by the Chinese Communist Party.
"To do what has been claimed against me in extravagant news reporting would be against everything I stand for."
The PM must reveal what he knew about Westminster's alleged Chinese spy, says Labour leader Sir Keir Starmer
Sir Keir Starmer has called on Rishi Sunak to reveal what he knew about Westminster's alleged Chinese spy.
Speaking while on a school visit in Dagenham, east London, the Labour leader said: "China is a strategic challenge, that's for sure.
"And what we need is a policy that is clear and is settled. And we haven't had that for the last ten years. We've had division and inconsistency from this government.
"And I think this morning the very big question now for the prime minister, which is was this raised when these arrests took place back in March or has it only been raised now that it's come into the public domain?
"I think that's the central question that needs to be answered by the prime minister today."
In the wake of the arrest, pressure is growing on Mr Sunak to designate China as a national security threat.
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Home Secretary Suella Braverman and Security Minister Tom Tugendhat are reported to be among those pushing for the move, the Times said.
Asked whether Foreign Secretary James Cleverly had known about the arrest when he travelled to China, the prime minister's official spokesman said: "On a specific case, I can't get into the detail I'm afraid, this is a live investigation.
"You would expect ministers to receive relevant updates on security issues."
Downing Street said it could not say whether the prime minister's intervention on the weekend was the first time the issue had been raised by the UK with the Chinese government.
Commons Speaker Sir Lindsay Hoyle moved to reassure MPs of security measures in the House of Commons, saying they are kept "under review at all times".
In a statement he said: "This is an ongoing, sensitive investigation and members will of course understand that public discussion will be wholly inappropriate.
"However, I want to reassure members that the House follows the same vetting procedures as the government, that issues raised by media stories are being addressed and that the security is working closely and effectively with other relevant authorities."
The Briton was arrested along with another man by officers on March 13 on suspicion of spying for Beijing, it was revealed by the Sunday Times.
Officers from the Metropolitan Police's Counter Terrorism Command, which oversees espionage-related offences, are investigating.
One of the men, in his 30s, was detained in Oxfordshire on March 13, while the other, in his 20s, was arrested in Edinburgh, Scotland Yard said.
Both were held on suspicion of offences under section one of the Official Secrets Act 1911, which punishes offences that are said to be "prejudicial to the safety or interests of the state".
Asked what reassurance it could provide to people who may feel Mr Tugendhat had been compromised amid reports that the man had access to him, the prime minister's official spokesman said: "Obviously we have robust processes in place and advice available."
Downing Street refused to say whether any extra vetting was taking place within the civil service following the revelations, nor whether checks had been strengthened after MI5 raised an alert last year warning that a suspected Chinese spy had engaged in "political interference activities".
"I can't get into our approach to security, what measures we do or do not take, in response to specific threats," the spokesman said.