Peter Tatchell has called on the Prime Minister to make an apology on behalf of the nation to mark the 50th anniversary of the part-decriminalisation of homosexuality.
In 1967, Parliament voted to change the Sexual Offences Act in order to legalise gay sex in private between men over the age of 21 in England and Wales.
Tatchell, a gay man and a long-term human rights campaigner, said the de-criminalisation was "limited", citing some of the ways homosexual men had suffered in the intervening decades.
He told Julia Hartley-Brewer: "It’s very important on the 50th anniversary to remember the decriminalisation of 1967 was partial and limited.
"It didn’t repeal any of the anti-gay laws, it just exempted men from prosecution in narrow circumstances.
"The irony is in the years after 1967, the number of gay and bisexual men convicted of consensual behaviour rose by over 400%.
"I’ve called on the Prime mInister Theresa May to use the occasion to make a public apology on behalf of the nation to the thousands of gay and bisexual men who suffered prosecution under discriminatory, unjust anti-gay laws."