Two bids have been made to improve the listed building status of Sir Arthur Conan Doyle's former home in Surrey.
The house in Hindhead was at the centre of a High Court battle last year when campaigners successfully fought against plans to turn it into flats.
Earlier this year, the late Sherlock Holmes creator's home was put up for sale, campaigners said.
English Heritage said it had received two bids to increase protection for the Grade II listed site.
'Not Jane Austen'
John Gibson, founder of the Undershaw Preservation Trust, said he made the first bid to change the Grade II listing to Grade I, which was rejected.
English Heritage said a second bid from an unnamed applicant had also been made to raise the listing to Grade II* which was being considered.
Mr Gibson said English Heritage told him Conan Doyle's home was "not in the same category as Dickens and Jane Austen".
Commenting on the trust's bid, a spokesman for English Heritage said: "After careful consideration of the evidence provided at that time, the Department for Culture, Media and Sport (DCMS) decided that Sir Arthur Conan Doyle's former home did not have the exceptional historical and architectural interest to merit upgrading."
Mr Gibson said he had the backing of over 500 academics for upgrading the listing status of the author's home.
He said Conan Doyle had created the "most instantly recognisable character in all fiction" and was regarded as the master of detective fiction and all that followed - but said he believed Conan Doyle's work was still not considered good enough to be "literary fiction".
He said he had now taken his fight to Culture Secretary Maria Miller in a bid to overrule English Heritage's decision.
The DCMS said English Heritage was looking at the case and would submit a recommendation in due course.
'Nursing home plan'
Mr Gibson said increased protection would bring the property under the responsibility of English Heritage instead of Waverley Borough Council.
He claimed Waverley council had "washed their hands of dealing with the property".
Tom Baker as Sherlock Holmes
Campaigners want to preserve the building as it was in Conan Doyle's days, and potentially see it used as a museum or visitor centre.
"I have spoken to developers who want to turn it into a nursing home and they said they wouldn't be interested if it had Grade I listing. We want Grade I," Mr Gibson said.
Waverley council said: "Ultimately it is for English Heritage to decide upon any amendment to the current listing of the property."
It said it did not own the building and was not involved in marketing it.
The council added: "Whilst it is the responsibility of the owner to maintain the property, the council does monitor the situation and is content that it is currently secure and watertight."
source : www.bbc.co.uk