MI5 will double its investigations into China in the face of the “game-changing” threat posed by the ruling Chinese Communist Party (CCP), the head of the security service said in an unprecedented speech about the espionage risk presented by Beijing.MI5 head Ken McCallum said the agency is running seven times as many probes into China as it was four years ago, and plans to “grow as much again” to tackle the widespread attempts at inference.The director general mentioned the security alert issued to parliament earlier this year over Christine Lee, a suspected Chinese spy accused of targeting MPs , as…