The Government says the designer of the Spitfire fighter, Reginald Mitchell, cannot be honoured after his death.
R J Mitchell "was as important to Britain as Nelson"
Their response comes after American billionaire Sidney Frank began a campaign for recognition of North Staffordshire-born Mr Mitchell.
However, the government has said honours such as knighthoods or OBEs are not granted after death.
The army also said posthumous awards are only given for acts of bravery.
Mr Frank has committed $1m to the campaign to honour Mr Mitchell.
Mr Frank has donated $1m to the campaign for an official honour
He told BBC News: "I think he was just as important to Britain as Nelson.
"Nelson saved you from the French and the Spanish fleets, and R. J. Mitchell had to save you from the hordes of Germany."
He has the support of members of the R J Mitchell Society.
Spitfire pilot Ken Johnson said: "It just seems appropriate that he should be recognised somehow.
"If the law says he cannot be given a knighthood, then maybe the law should be changed. He certainly deserves it."