Men who have been convicted for homosexual acts on the Isle of Man will be automatically pardoned later this year in what campaigners said was a long overdue and necessary change in law.

Homosexuality was decriminalised on the Isle of Man in 1992 and its first Gay Pride event took place last summer.

Jane Poole-Wilson, the home affairs minister, said new legislation would come into force in June at the latest.

The new act will pardon those convicted for a historical sexual offence if the act in question is no longer a crime. While the pardons will be automatic, people will have to apply to have historical convictions struck from their records in a “disregard process”.

Two years ago the island’s then chief minister apologised for the way gay men had been treated, having had their homes raided and been put on trial for consensual sexual activity.

“Our previous laws discriminated against and criminalised men solely for who they were and who they loved,” said Howard Quayle.

“The previous law reflected a different time, a different place. An island of the past. Those who were convicted of these crimes, and their loved ones, should no longer have to shoulder the burden of guilt. They should be seen as innocent.

“All those people affected – the men themselves, their partners, wider family and friends – they deserve an unqualified apology from us.”

The forthcoming pardons were welcomed by Alan Shea, a hero of the Manx battle for gay rights. On 5 July 1991, the Manx bank holiday of Tynwald Day, he wore a concentration camp uniform fashioned from Marks & Spencer pyjamas to petition parliament to legalise homosexuality, making parallels with the Nazi persecution of gay people.

Soldiers hissed at Shea as he walked to Tynwald Hill to argue that he should not face life in jail just for having sex with his partner, Stephen Moore, now his husband. On camera, a furious man denounced Shea and his friends as local children looked on with interest.

“It’s good that people are finally being pardoned, but we are still waiting for an apology from the chief constable of the Isle of Man police to apologise for the way the force persecuted gay people,” said Shea.

He was unable to get a job for 10 years after The Tynwald Day protest and claims his house was put under constant surveillance by police, questioning everybody who came in and out.

Shea was never arrested but has friends who were, some of whom left the island, never to return. “Many of them are still haunted with memories of what happened,” he said.

Peter Tatchell, the gay rights campaigner, said: “This decision is long overdue and necessary given the intense persecution LGBT+ people faced on the Isle of Man in the decades after homosexuality was significantly decriminalised in the rest of the UK.”

He echoed Shea’s call for a police apology, saying: “The Isle of Man police went out of their way to target and persecuted gay and bisexual men and conducted a witch-hunt that was unprecedented in the UK.”

In 2017 the UK issued thousands of pardons for gay men, after the 2013 royal pardon granted by the Queen to Alan Turing, the mathematician who broke the German Enigma codes during the second world war. He killed himself in 1954, at the age of 41, after his conviction for gross indecency.

The Isle of Man is not part of the UK but is a self-governing British Crown Dependency with its own parliament, government and laws. The UK government, on behalf of the crown, is ultimately responsible for its international relations and defence, and provides consular services for its 84,000 citizens.