In the book, De Mowbray's claims are the subject of a chapter subtitled "Paranoid tendencies" which recounts his work as well as that of two colleagues, Peter Wright (author of the controversial Spycatcher) and Arthur Martin. The book quotes an MI5 director saying of the group: "Involvement in counter-espionage cases induces in some a form of paranoia." De Mowbray himself is referred to - although not by name - as "the leading SIS (Secret Intelligence Service) conspiracy theorist"; he is connected to the work of 'spycatcher' Peter Wright, whom the government sought to silence in the eighties for his embarrassing revelations about the service. The official line seems to be that in his search for infiltrators de Mowbray became over-zealous and prey to the exaggerations of the agents providing the information.
[* XTC fans may get in title reference to the track from the Dukes of Stratosfear's 25 o'clock album!]