All gay men convicted under historic indecent laws should be granted an automatic pardon, Labour leadership candidate Andy Burnham has said.
The party pledged at the general election to extend to family and friends surviving individuals' right to apply for convictions for now-legal activities to be quashed.
But the shadow health secretary said legal advice backed from a former head prosecutor suggested Parliament could simply legislate for a blanket pardon.
Pressure for wider action has grown since a posthumous royal pardon was granted in 2013 to Second World War code-breaker Alan Turing after a campaign led by his family.
“Alan Turing made a remarkable contribution to our country, but it is not only national heroes that deserve to have their suffering atoned for," he said ahead of a hustings for the four leadership rivals in Brighton.
"Tens of thousands of men were treated appallingly and every one of these convictions is equally shameful.
"I was one of the first Labour frontbenchers to call for equal marriage and I believe the next frontier is a law to remove this shadow from our national history.
"It would send a strong message to millions of LGBT individuals around the world, who still live in fear of persecution, and to the governments and national leaders that refuse to recognise equal rights."
Sir Keir Starmer, the former director of public prosecutions elected a Labour MP in May, said: "Automatic pardons are appropriate in these cases, not only to mark the grossly unjust basis of the convictions but also to send a powerful message to the world about the unacceptability of similar anti-gay laws still in existence."