Military personnel and veterans dismissed or stripped of their medals because of their sexuality are to have them restored.
The Prime Minister says a new Ministry of Defence (MOD) scheme, which invites LGBT (lesbian, gay, bi and trans) service personnel to apply for their medals to be reinstated if they lost honours due to their sexuality, addresses an "historic wrong".
Homosexuality was banned in the Armed Forces until 2000, more than three decades after it was decriminalised in civilian society.
"Those who serve in our Armed Forces deserve every recognition for their service," Boris Johnson said.
"It was a very great injustice that this was denied to some members simply because of their sexuality.
"I hugely welcome the fact we can now address this historic wrong."
Former Royal Navy officer Craig Jones received an MBE for his services to equality and human rights in the Armed Forces.
"People were found out, they were taken away by the Special Investigation branch of the Royal Military Police," he said.
"They were interviewed, sometimes that felt like an interrogation, they were charged and sent to Court Martial.
"At Court Martial, people routinely received a sentence of between two weeks and six months."
Former RAF officer Caroline Pearce became the first openly trans officer to serve.
"For the first 18, 19 years of my service career I had to hide who I was because there was this fear that I would be outed, and therefore I would lose my job, my house, my income, my family and friends and everything," she said.
After transitioning, she says her career thrived.
"I went out to Iraq, I went out to Afghanistan, won awards for exceptional service out there," Caroline added.
Both Caroline and Craig co-chair the campaign group Fighting With Pride and want more to be done to support veterans ostracised for their sexuality in the past.
Under the new MOD scheme, affected personnel can apply to have their case reviewed by the Defence Council, with service records being examined.
Successful applicants will receive a new medal from the MOD's Medal Office.
Relatives of affected ex-military members who have since died are also able to apply for a review.
A statement on the GOV.UK website says: "Prior to 2000, a number of Armed Forces personnel were discharged from service on the basis of their sexuality.
"Some received convictions under specified legislation for homosexual behaviour that has now been de-criminalised, while others were discharged solely on the basis of their sexuality, without any conviction.
"In the course of their discharge, some personnel either forfeited medals directly or were prevented from continuing to serve and thus denied the ability to regain medals that might previously have been forfeited for unrelated reasons.
"The MOD is committed to addressing this historical wrong and is introducing a policy which enables individuals to apply to have their medals restored."
Last year marked two decades since the ban was lifted on lesbian, gay or bisexual personnel serving in the Armed Forces.
Until the lifting of the ban in 2000, personnel who were gay faced a dishonourable discharge from the military.
Since then, civil partnered couples now receive the same benefit as married couples and same-sex couples are able to live together in all service accommodation.
Last year, the British Army and RAF featured in the top 100 employers list published by LGBTQ+ rights charity Stonewall.
The British Army and the Royal Air Force both dropped in the rankings, while the Royal Navy did not enter to be featured.
The Army was ranked 82nd in the list, while the RAF was in 90th position.