Hawking urges PM to pardon Enigma codebreaker

Professor Stephen Hawking is one of 11 leading scientists to write the letter Credit: Reuters/Jonathan Weitzman

Professor Stephen Hawking has urged the Prime Minister to posthumously pardon Enigma codebreaker Alan Turing, who was convicted of homosexuality in the 1950s.

Prof Hawking is one of 11 leading scientists who, in a letter to The Daily Telegraph, called on David Cameron to "formally forgive" the mathematician, whose work at Bletchley Park is widely credited with shortening the Second World War by two years thanks to the vital military secrets it uncovered.

Other signatories include the Astronomer Royal Lord Rees, Royal Society President Sir Paul Nurse and Lady Trumpington, who worked for Mr Turing during the war.

The letter comes after Lord Sharkey, also one of the signatories, introduced a Private Member's Bill in the House of Lords seeking to officially pardon the codebreaker.

Mr Turing died from cyanide poisoning two years after being convicted of gross indecency at a time when homosexuality was illegal. An inquest ruled it was suicide.

In the letter, the scientists describe him as "one of the most brilliant mathematicians of the modern era", and they pay tribute to his "astonishing achievement" in breaking the German Enigma code.

It goes on, "Yet successive governments seem incapable of forgiving his conviction for the then crime of being a homosexual".

The Pilot ACE computer, fundamentally designed by Alan Turing, was the world's fastest computer Credit: Geoff Caddick/PA Wire

"We urge the Prime Minister to exercise his authority and formally forgive the iconic British hero", they add.

While he was Prime Minister in 2009, Gordon Brown issued a posthumous apology to Mr Turing and described his treatment as "appalling", but he did not offer an official pardon.

Earlier this year, the Government introduced legislation allowing people previously convicted of homosexuality to have the offence removed from their criminal record.