Claims that MI5 members conspired against the then prime minister will be given a fresh airing tonight in a BBC documentary, which suggests that senior military officers and even members of the Royal Family tacitly endorsed a planned coup d'tat.
However, the intelligence agency has issued what amounts to a public denial of any conspiracy.
Although MI5 does not comment publicly on its activities, it maintains a public website, that was yesterday updated with an entry about "The Wilson Plot".
The entry seeks to undermine the credibility of Peter Wright, a former MI5 officer who wrote of a plot against Wilson in his 1987 book Spycatcher.
Wright's evidence is "discredited," MI5 says, pointing to the former officer's own admission that his memory of discussions with colleagues about Wilson was "unreliable".
The Security Service's latest contribution to the debate on Wilson's fear of persecution is unlikely to allay suspicions of a plot against him.
Careful readers will note that nowhere on its internet posting does MI5 deny that some of its members did, indeed, consider removing Wilson from office.