The government agency, which runs the scheme, rejected the application by supporters of the founder of Scientology after its blue plaques panel decided that it was unconvinced about Mr Hubbard's "reputation".
The decision has frustrated the Hubbard Foundation, which had nominated him. In an unusual move, a foundation representative went to visit English Heritage officials, following the verdict, to find out more about why he had been rejected and how his case could be helped.
Under the rules of the scheme, no candidate can be reconsidered within 10 years of being rejected, but Mr Hubbard's backers say they do not consider the matter "closed" and are now proposing further talks in a bid to revive their cause.
The organisation, which is considered a cult by some, is based on the premise that the human race is descended from Thetans, an exiled race from another planet.
It was founded by Mr Hubbard, an American science fiction writer, in the 1950s, and now has millions of followers including the Hollywood actors Tom Cruise and John Travolta. From 1957 until 1959, Mr Hubbard based himself at Fitzroy House, in London's West End, and wrote many of his works there. It was a Scientology "church" until 1968, when it was sold. The organisation then bought it back around six years ago and the four-storey building, at 37 Fitzroy Street, is now open as a museum in Mr Hubbard's memory.
According to minutes of a meeting in June last year, obtained using Freedom of Information legislation, the blue plaques panel decided that "more time was needed to make an objective assessment of Hubbard's reputation". Panel members present at the meeting included Professor Andrew Motion, the former Poet Laureate.
The panel "also noted that [Hubbard] had no settled residence in London". However, other foreign personalities who only spent short periods of their life in the capital have been awarded plaques in their honour.
Blue plaques are considered a high accolade and have been erected outside the London homes of some of the world's greatest minds. Eligibility guidelines state that nominated figures must have been dead for 20 years or have passed the centenary of their birth, and must have made an "important positive contribution to human welfare or happiness". Mr Hubbard died in 1986.
A source who was involved in the deliberations said: "The decision was on the grounds that he wasn't well known or well respected enough. Controversies surrounding him come into the well-respected bit. The committee was not divided on this, I think."
Sarah Eicker, director of Fitzroy House, who nominated Mr Hubbard, said: "I met with the administrator of the panel to get more data and clarify why the decision had been made.
"I am planning to set up another meeting. I am aware of the 10-year rule. I don't think the initial proposal is a closed thing.
"I definitely think Mr Hubbard warrants a plaque. Maybe the information we provided wasn't sufficient."
She said some of the controversies surrounding the movement "might have" played a part in the decision. "I would hope not," she added. "I would have hoped their decision was made objectively."
Ms Eicker insisted that Mr Hubbard was "well respected" enough to warrant a plaque, and said she would be asking English Heritage whether they had "discriminated" against Mr Hubbard.
"I don't know if there was discrimination or not," she added.
She said some of Scientology's well-known followers had visited the London property, but declined to reveal which ones.
The number of Scientologists has been put as high as 12 million, but the movement remains controversial. The organisation has been described in Parliament by Michael Gove, the Tory MP, as "an evil cult founded by an individual purely in the interests of enriching himself and sustained by those who are either wicked or wayward".
Recently, it was branded a "criminal organisation" in Australia, after a politician used parliamentary privilege to detail a series of allegations against its members there, including assault, imprisonment, embezzlement of church funds and blackmail. It was also claimed that the church had exerted pressure on some members to have abortions.
A spokesman for English Heritage said: "It was felt that since Mr Hubbard had died only relatively recently, in 1986, that more time was required to make an objective assessment of the importance and longevity of his achievements.
"The panel also noted that Mr Hubbard had no address in London which could be considered as comparatively settled, and moved around a great deal.
"If a proposal is not successful, it can be put forward again 10 years from the date of rejection, and English Heritage encourages proposers of plaques to take advantage of this."
