A bid has been launched to raise the money to buy Enigma codebreaker Alan Turing's papers for the nation.
The documents are expected to fetch between £300,000 and £500,000 when they go under the hammer next week at Christie's auctioneers.
So time is running out for IT journalist Gareth Halfacree, who has so far raised only £15,000 through an internet campaign.
His bid has the support of the Bletchley Park Trust.
A trust spokeswoman said: "It would absolutely marvellous if we could get the papers but he's obviously up against it as far as raising the money in the time he's got."
Alan Turing is famous for his code-breaking work at Bletchley Park during World War II, helping to create the Bombe machine which cracked messages enciphered using the German Enigma code.
He committed suicide in 1954, two years after being prosecuted for having a sexual relationship with a man.
Last year thousands of people signed a Downing Street petition calling for a posthumous government apology to Turing.
The then prime minister Gordon Brown responded by saying he was sorry for the "appalling" way Turing was treated for being gay.
Mr Halfacree told the BBC: "These papers are extremely significant."
During Turing's sadly truncated life he only published 18 papers and Christie's says the auctions is for offprints of 15 of them, which were given by Turing to his friend Professor Max Newman.
Mr Halfacree said: "There are handwritten notes by Turing on them and one of them has the signature of his mother on it."
He said they were up against private collectors from all around the world: "The sort of people who will probably want to buy them will be Silicon Valley entrepreneurs and anyone who is aware of their historical significance.
"Turing invented the modern universal computer. His machines were the birth of modern digital computing."
He said any money donated through his Justgiving webpage would go directly to Bletchley Park Trust, which is always in need of money and is trying to preserve the radio shacks which the codebreakers used.
Mr Halfacree said most of the money generated so far had come from social networking sites and he said he was desperately trying to get the attention of author and broadcaster Stephen Fry, who has expressed support in the past for Bletchley Park.
"He has almost two million followers on Twitter and if each one donated 5p it would be enough to raise what we need. But it's a question of getting through the noise. Every day so many people are trying to get him to Tweet things," he added.