Miliband to offer pardon for historic homosexual convictions.

New legislation known as Turing’s Law - in memory of Enigma code-breaker Alan Turing, who was given a posthumous royal pardon for a 61-year-old conviction - will allow family and friends of men who have died to bid for their names to be cleared.

It will apply to convictions under old gross indecency laws against men who had consensual same-sex relationships.

The Labour leader said: “What was right for Alan Turing’s family should be right for other families as well.

“The next Labour government will extend the right individuals already have to overturn convictions that society now see as grossly unfair to the relatives of those convicted who have passed away.”

Dr Turing, who was pivotal in breaking the Enigma code, arguably shortening the Second World War by at least two years, was chemically castrated following his conviction in 1952.

His conviction for “gross indecency” led to the removal of his security clearance and meant he was no longer able to work for Government Communications Headquarters (GCHQ), where he had continued to work following service at Bletchley Park during the war.

Dr Turing, who died aged 41 in 1954 and is often described as the father of modern computing, was granted a pardon under the Royal Prerogative of Mercy by the Queen following a request from Justice Secretary Chris Grayling.

A pardon is only normally granted when the person is innocent of the offence and where a request has been made by someone with a vested interest such as a family member. But on this occasion a pardon has been issued without either requirement being met.

In September 2009, then-prime minister Gordon Brown issued an apology for the prosecution of Dr Turing after a petition calling for such a move.

Campaigners, including the code-breaker’s family and actor Benedict Cumberbatch, who played him in The Imitation Game, have called for the pardons to be extended to tens of thousands of other British men convicted under old laws.