Xi's right-hand man Cai Qi, trusted official suspected of being at heart of UK spy ring

In a world of identikit bureaucrats, Cai Qi, the man described as Xi Jinping's top lieutenant and recently revealed as the suspected heart of an alleged Westminster Chinese spy ring, stands out.

- Amy Hawkins

As the fifth-ranking member on the standing committee of the Chinese Communist party's ruling politburo, Cai is one of the most powerful people in China. But his importance outstrips even his senior title, because as the Chinese leader's de facto chief of staff, he is also effectively the gatekeeper and right-hand man to Xi himself.

Unlike other top CCP officials, Cai shuns the black hair dye.

He is said to speak with a heavy Fujian accent, rather than the standardised Mandarin that Beijing promotes across the country. His rapid ascent has made it clear to observers of Chinese politics that he is deeply trusted by Xi.

On Wednesday, in an attempt to fight back criticism that Downing Street had sabotaged the trial of two men accused of spying for China, the government released in full the witness statement written by the deputy national security adviser Matthew Collins for the Crown Prosecution Service (CPS).