The memoirs of most pop stars follow a formula, describing in lurid detail their sexual exploits and battles with drug addiction. Sir Cliff Richard's autobiography is a little different, if no less illuminating.

The 67-year-old singer has spoken for the first time about his close relationship with a former Roman Catholic priest, and calls on the Church of England to approve same-sex marriages.

Sir Cliff describes how he struck up an intimate friendship with an American former missionary, Fr John McElynn, after meeting him in New York seven years ago. The famously clean-cut pop singer reveals that he hired Fr McElynn to look after his charitable projects and numerous houses, after it became clear the American would give up the priesthood. The pair now live together.

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In the book, Sir Cliff calls the former clergyman his "companion" and "blessing", going on to say he is "sick to death" of media speculation about his sexuality. "Our arrangement has worked out really well," he writes. "John and I have over time struck up a close friendship. He has also become a companion, which is great because I don't like living alone, even now."

Sir Cliff, a poster boy for the Christian faith, also defends his decision to remain a bachelor in the book, titled My Life, My Way. "People often make the mistake of thinking that only marriage equals happiness," he writes.

"I may suddenly meet someone and feel differently, but right now I am not sure marriage would enhance my happiness. As for my sexuality, I am sick to death of the media's speculation about it. What business is it of anyone else's what any of us are as individuals? I don't think my fans would care either way."

He calls on the Church of England to update its views on same-sex marriages, arguing that all judgements on sexuality should be left to God. "I think the Church must come round and see people as they are now. Gone are the days when we assumed loving relationships would be solely between men and women. It seems to me that commitment is the issue, and if anyone comes to me and says: 'This is my partner; we are committed to each other', then I don't care what their sexuality is. I'm not going to judge; I'll leave that to God."

Sir Cliff chose the Lakeside Shopping Centre in Essex to sign copies of his book yesterday. More than 1,000 fans, mostly female, turned up. In the book, Sir Cliff, who has sold more than 250 million records over six decades, reveals that the only two women he considered marrying were the dancer Jackie Irving and Sue Barker, the sports presenter. He describes Ms Irving, with whom he had a relationship in the early 1960s, as "utterly beautiful", and says for a time they were "inseparable". She married Adam Faith.

Sir Cliff met Sue Barker in 1982. They quickly formed a close attachment thanks to their shared passions for tennis and Christianity. "I seriously contemplated asking her to marry me," he writes, "but in the end I realised that I didn't love her quite enough to commit the rest of my life to her. There were no broken hearts."

He also describes the time he was famously seduced by Carol Costa, the estranged wife of Jet Harris, a member of his backing group, The Shadows. "I was surprised but not unhappy to be seduced", he writes , but stresses that "sex is not one of the things that drives me". In 1996, he flatly denied he was gay. "I'm aware of the rumours, but I'm not gay."

Steve Turner, who wrote a biography of Sir Cliff in 1993, said: "Of all the people I've interviewed, from David Bowie to the Beatles, he's the one most people ask me about. With Cliff, there's always that element of uncertainty and puzzlement, because there's something unresolved about his image."