The blonde star - the daughter of Bob Geldof - has joined the campaign to legalise gay marriage in the UK and is astounded at how many people are still opposed to it in modern society.
Peaches said: "For a country and culture that declares ourselves so progressive, our governments, citizens and, of course, our churches, can be small-minded bigots at the best of times.
"One day we'll look back on the gay marriage ban as we look back on historical events like apartheid.
Because in the end, that's what it is - pointless, futile segregation."
One of the reasons why the 23-year-old pop star feels so strongly about this cause is because she grew up with a gay best friend, Ben, and saw first hand the "devastation" that he experienced when he came out to his parents and told them he was dating Peaches' other friend Daniel.
Writing in an article for the Independent Voices website (www.independentvoices.com), she revealed: "I sat there, on the same patch of grass in Cavendish Square, worn down from our school shoes, and my friend wept as the words left his mouth.
"I grieved for them, knowing I could never take the words back for him myself. His mother was devastated, his father, in his words, 'ruined'.
"They both told him he was sick and a failure. He left home. How, of course, could he have stayed. I think, after that, Ben hated Daniel a little bit, partly because he had pushed him to come out, partly because he was jealous. But in the end he loved him more, and Daniel's parents allowed him to move in to their house and live there with him."
Ben and Daniel eventually got married in a ceremony in New York several years after the incident.
Peaches wrote the article to support Independent Voices' EQUAL PARTNERS campaign to fully legalise gay marriage in Britain.
The EQUAL PARTNERS manifesto's aims are for civil marriages to be extended to homosexual couples and for religious institutions to be free to marry homosexual couples.