The head of MI5 says he will "never back off" from confronting threats from China as he revealed his officers disrupted a case linked to Beijing in just the past week.

More broadly, Sir Ken McCallum said the number of people in the UK under investigation for "state threat activity" - also including from Russia and Iran - has jumped by 35% in the past year compared with the previous 12 months.

He admitted he felt frustration at the collapse last month of a trial against two British men accused of spying for China , but he stressed that the Security Service had still successfully derailed the alleged espionage operation.

With pressure mounting on Sir Keir Starmer over why the high-profile trial foundered, the director general of MI5 - choosing his words carefully given the controv

See Full Page