Morrissey: The Alan Bennett of pop

Viciously vegetarian, aloofly sensual, the troublesome singer is both national treasure and scourge

When Morrissey hit the headlines last week, condemning Oxford's new animal research laboratory, it was business as usual. He branded the city "the shame of England", and warned lab workers, "We will get you." The singer, who has been a vegetarian since he was 11, declared, "If you agree with vivisection, go and be vivisected upon yourself."

Morrissey at 47 may be mellowing in some ways (once famously celibate, he has even hinted at a late-blooming sex life), but he will never be cuddly. For the past two decades, his songs have embraced taboo subjects, from Northern Ireland and domestic violence to thalidomide and the Moors murders. A celebration of the outsider is a constant theme. "People tend to see him as an elder statesman now, but he's always been radical," says the rock journalist Fiona Sturges. The irony is, Middle England now seems keen to co-opt him.

The apotheosis came last week when the Tory leader, David Cameron, chose The Smiths' "This Charming Man" onDesert Island Discs (seemingly unaware that the song is about age-gap, gay sex).

"He was the 1980s' greatest outsider, vehemently opposed to everything that decade stood for," says Mark Simpson, the author of the biography Saint Morrissey. "Now he's seen as the 1980s' greatest artist - especially by people who hated The Smiths at the time."

Morrissey's anti-vivisection speech delivered a slap to the Establishment. The "Pope of mope" may be adored for his lyrics about alienation and failed love, but he has always been overtly political. A sworn enemy of Margaret Thatcher, his first solo album included the track "Margaret on the Guillotine". Police reacted by searching Morrissey's home and making him the subject of an official investigation. Today he rubbishes the Bush administration's foreign policy, loathes Tony Blair and is a vocal opponent of the Iraq war. He remains a life-long anti-monarchist too: "I'm not fooled by William or Harry, who just seem like arrogant, despicable people," he told a journalist recently.

And, not surprising for the man whose 1985 track "Meat is Murder" featured the authentic sounds of cows being led to slaughter - and turned a generation vegetarian - animal rights are close to his heart. "Would you eat your cat?" he asked Jonathan Ross.

"He's made it clear that he identifies strongly, perhaps unhealthily, with the plight of defenceless animals," says Simpson. "Maybe because of his painful adolescence, locked up in his bedroom." Last month, Morrissey announced he was boycotting Canada in his world tour in protest against the country's annual seal hunt. Critics muttered that it was a great way to promote his new single.

Steven Patrick Morrissey is one of the great pop enigmas. He can be aloof and mysterious yet has an unerring ability to communicate. It is hard to convey the shock he first caused in 1982 as the lead singer of Manchester indy band, The Smiths. In an Evans outsize blouse, NHS glasses and a hearing aid, he was a poster boy for misfits everywhere. Pop was not accustomed to such sardonic humour and acidic wit. Only 15 years after homosexuality had been decriminalised, his lyrics flirted with every kind of gay subculture. And yet, his most passionate fans are heterosexual men.

Born in 1959 in Manchester to working-class Irish-Catholic immigrants (father a hospital porter, mother a librarian), he had a bumpy childhood. Today he is close to his mother and sister, but has no contact with his father. Hugely intelligent but undisciplined, he ended up at a sink secondary modern. He claims his schooldays were "barbaric". He has always battled depression. Music was his way out. "As a child I would sing every single night - and the neighbours would complain - because I had this insane desire to sing."

Leaving school in 1975, he worked briefly for the Inland Revenue before the dole. He was a classic bedroom pop obsessive. In 1982, guitarist Johnny Marr walked into his life. Morrissey showed him the lyrics he had written; Marr set them to music; they hired two other musicians and within a year they were famous. Marr and Morrissey fell out and the band broke up in 1987.

Morrissey began a successful solo career but found himself marginalised by hip-hop and dance music. He was vilified for performing at the first Madness reunion show at Finsbury Park, draped in the Union flag. The NME debated whether he was a racist after comments about hating reggae. Morrissey commented, "If the National Front were to hate anyone, it would be me." Sturges observes, "Finsbury Park was only four years before Ginger Spice wore the Union Jack frock, and Britpop was all about nationalism and pride in your country. Morrissey has always had that very parochial concern about Englishness ... he's the Alan Bennett of pop."

Morrissey didn't help his case with an uneasy flirtation with gangster imagery: he took up boxing and was accompanied everywhere by a skinhead, Jake. The man who abhorred violence became strangely fascinated by it. Then, in 1996, The Smiths' drummer Mike Joyce sued Morrissey and Marr for outstanding royalties and won. The judge presiding over the case famously ruled that Morrissey was "devious, truculent and unreliable".

For five years, he was without a record contract and lived on Sunset Boulevard, in the house Clark Gable bought for Carole Lombard. In 2003, Sanctuary Records announced a new deal: he was given the one-time reggae label Attack Records as a platform to record new material and sign new artists.

His first album, 2004's You Are the Quarry, was released to favourable reviews. Then came Ringleader of the Tormentors, which went to number one in the UK charts earlier this year.

Lyrically it has been hailed as his most explicit yet. "Morrissey has always had this uneasy relationship to sexuality," says Sturges, "like that great quote when he said his genitals were the result of some terrible practical joke." Not any more. In "Dear God, Please Help Me", he sings, "There are explosive kegs between my legs."

Morrissey's sexuality has been a vexed issue for everyone but himself. For years he pioneered radical celibacy. As Kathy Burke put it: "A good-looking bloke who don't fuck - very cool!" He says there have been lovers, but nobody has ever kissed and told.

After six years in Los Angeles he has moved to Rome. Rumour has it he is in a new relationship. He denies it: "Everything remains the same. I am an island."

Simpson thinks a lot of rot has been talked about Ringleader of the Tormentors being Morrissey's coming-out album. "He has never pretended to be straight, but then, he clearly doesn't believe in homosexuality or heterosexuality. For him, there is just sexuality - and it's a nightmare as much as it is a wet dream. For Morrissey, there is no happy, registered partnership ending."