The first instance of a nomination being made for a Blue Plaque for 21 Eccleston Square dates to 15 June 2000 when Robert Stephenson wrote Pam Whiffin of English Heritage saying "…I am now pleased to start it off by enclosing some relevant material about Markham and asking that he and his house be honored by a plaque." Copies of this letter were sent to the Royal Geographical Society (Mr Nigel de N. Winser, Deputy Director), Scott Polar Research Institute (Mr Robert K. Headland, Archivist and Curator), the Hakuyt Society (Mrs Sarah Tyacke CB, President) and to polar historian and author Ms Ann Savours. Each was invited to send a letter of support directly to English Heritage. The only confirmed letters of support were sent by Nigel Winser (with comments from John Hemming) and Ann Savours. Others may have been sent but Robert Stephenson was not copied.

The Commemorative Plaques Panel met in the Fall of 2000 and considered the nomination. Mr Geoffrey Noble, Blue Plaques Secretary, informed Robert Stephenson of the Panel's action in a letter dated 18 December 2000. To the surprise of many, the nomination was turned down. "I regret to say that, following advice from our Commemorative Plaques Panel, we have concluded that Sir Clements R. Markham is of insufficient stature, within the field of exploration, for commemoration under the scheme. In giving its advice the Panel noted that although Markham was undoubtedly an important figure in the world of geographical science and the Royal Geographical Society, they felt he was more of an administrator and promoter of exploration rather than an explorer himself, and that this was not sufficient to warrant commemoration with a plaque. Comparisons were made with figures already commemorated including, Captain Scott, Captain Flinders, Sir James Ross, Sir Ernest Shackleton and Edward Wilson."

Robert Stephenson responded to Mr Noble with a letter dated 7 January 2001: "It appears that he was being considered solely as an explorer—which as you point out he was but a minor footnote—and not as a multi-faceted individual devoting great energy to numerous activities, often behind the scenes and often with significant effect. If he were to be forced into a single pigeon hole, it would have to be, in my view, as the father (or mid-wife) of modern British Antarctic exploration. Without Markham, Scott, Shackleton and all the rest would not be household names (and now increasingly so)."

Questions were asked about appealing decisions of the Panel. The only avenue for proceeding is to reapply ten years or more after a nomination has been rejected.

This is how the matter has stood ever since.