Within months of Elvis Presley's death in 1977, the King of Rock 'n' Roll had been dethroned for many disillusioned fans by muckraking biographies that revealed lurid details of his drug-numbed final years.

Now one of England's most popular playwrights, Alan Bleasdale, an Elvis fan since age 10, has attempted to set the record straight in a musical that received a standing ovation when it opened here earlier this month.

"Are You Lonesome Tonight?" is less an attempt to whitewash a fallen idol than a plea for compassion as we scrutinize those we purport to adore.

"He was the closest thing to a Greek god the 20th century has ever known," says Bleasdale, 39, who grew up listening to "Heartbreak Hotel" in a working-class section of Liverpool, the Beatles' hometown. "He had an erotic genius never seen before. People had been used to Glenn Miller and Frank Sinatra. Johnny Ray was supposed to be exciting. And Pat Boone! And then this wonderful, charming, self-mocking, laughing animal came flying on to 'The Ed Sullivan Show' and nothing was ever the same. John Lennon said, 'Before Elvis, there was nothing.' We owe it to him to be fair."

The play takes place the day Elvis died. Nestled against three glittering Cadillac hoods on the upper level of a split set, a lanky, vibrant teen-aged Elvis intermittently breaks into "Jailhouse Rock" and "Hound Dog" while a disillusioned middle-aged Elvis stares wistfully at his former self from a pink Naugahyde hell below.

While Elvis the younger tantalizes the audience with his twitching, soon-to-be-legendary left leg, Elvis the elder lurches around the set like a wounded bear, clutching the black attache' case containing his arsenal of pills, as he frantically tries to prevent two former aides from selling "the truth" to a British journalist. ("People are interested in filth," Presley pleads. "If I heard that Burt Reynolds was a transvestite junkie, I'd be interested.")

So grotesque is the portrait of the surrealistically bloated, megalomaniac recluse subsisting on junk food and Dilaudid, a synthetic drug 2 1/2 times more powerful than heroin, that the president of one British fan club advised fans not to attend.

Critics have been lukewarm, and several have accused Bleasdale of further exploiting Presley. "I was against the vultures," the playwright says, "but I also knew I was performing yet another autopsy on a living, breathing human being who died too young. Either in my madness or my arrogance, I believe that I understood him better than even those people who lived with him -- the warmth and charm and nobility and generosity of spirit."

Neither Presley's opiate intake and his rumored taste for pornography nor his idea, reported by one biographer, to have professional killers murder his wife's lover has tarnished his talents in Bleasdale's eyes.

Throughout the play, Presley is presented as the victim of ultimately mitigating circumstances.

We are shown the possessive mother who passed on her obsession with Elvis' stillborn twin Jesse ("She set the table for four though there were only three," an aide says), with the result that Elvis always felt incomplete without the "better half" he'd been told had died to give him life.

A pink armchair identical to Elvis' own is always reserved for the invisible Jesse, to whom Elvis confides regularly throughout the play.

Presley's manager, "Colonel" Tom Parker, who in the end was taking a large share of Presley's earnings, pilots a gold-lame'-encased Elvis dummy around the stage followed by a succession of sycophantic cohorts who sneak off to sell the Presley story.

For Bleasdale, Presley's megalomania and seemingly infinite capacity for self-indulgence are understandable given the amount of adulation he received.

"If you tell someone he's a king long enough, anyone will come to believe it," says Bleasdale. "Who could survive being treated like a god?"

Most of all, Presley is portrayed as a victim of the American Dream. ("Mama," he confesses ruefully as he surveys his mountain of possessions, "I always thought that this 'n' this 'n' this would make it all right.")

"He came from the most abject poverty, poor white hillbilly trash, the lowest of the low in the America of the '50s," says Bleasdale. "People sneer at him for expressing his love with Cadillacs and mink coats, but those were the only values he had," adds Bleasdale, who calls Elvis the only true working-class hero.

"Lennon and Dylan are always described as working class, but they weren't. Lennon lived in the best part of Liverpool. They may have represented the working class, but they had middle-class values, awareness and intelligence that helped them survive. All Elvis had was this one huge revolutionary talent and not a lot to go with it, nothing but his sideways smile and his left leg. He had no armor. He never understood the way the world worked. He wasn't a survivor the way the others were. It's ironic. People think of him as a rebel, but the man never rebelled in his life. If he had, he might be alive today."

In one of the most powerful scenes of the play, Elvis askes the invisible Jesse how he would have handled the colonel, the Army, and his ex-wife. "The difference between us, Jesse," Elvis cries, "is that you would have won, you would have gotten some control over your life."

The same sense of helplessness pervades another scene, where Elvis gives a $43,000 diamond ring to the cook who stayed up singing hymns with him. "You took me away from where I was heading," he explains, "and I didn't really want to go there."

Bleasdale would like the show to go to the United States but wonders about the reception it would get. "It's really an American tragedy. I don't know whether Americans in 1985 are ready for a musical about a loser."

Predictably, it is the electric performance by Simon Bowman, the hitherto unknown 24-year-old Welsh actor who incarnates the younger Elvis and sings the most famous songs, that keeps the play from being submerged under waves of self-pity emanating from Elvis the elder below.

Bowman sounds remarkably like Elvis, and offers from record companies have been pouring in. "Bowman's performance makes up for the fact that Elvis never came to England," wrote a critic who seemed to speak for fans who broke into choruses of "Oooh" during the London opening.

Both Bowman and Martin Shaw, 40, who has the more demanding and less glamorous role of the aging star, spent weeks watching videos of Elvis on stage and "The Ed Sullivan Show" to get their gestures and southern accents right.

Shaw strains for such authenticity that his southern mumble is sometimes unintelligible, and the performance suffers from the fact that several members of the cast are Canadians and Americans residing in Britain.

But Elvis fans love it anyway. "You wouldn't believe the wonderful letters I get," says Bleasdale. "The other night I found a scrap of paper on the floor of the theater. It said, 'To Alan with love and thanks and tears and laughter. You understand.' Signed B.J. Johnson, an Elvis fan." He paused to grin, a twinkle emerging from a sheepdog fringe of hair. "Does a boy's heart good."

Bleasdale has indentified strongly with Presley ever since he was a child. "I'm a poor redneck too, or the English equivalent," he said over tea, to calm his opening night nerves. "My mother was one of 13 children, my father one of 12. We lived in the poorest part of town and my dad would cycle to work because he couldn't afford the bus.

"Liverpool was the nearest major port to North America, and in the early 1950s, the dockers used to get all the jazz and blues records long before the rest of Britain. When I was 10, I was at my mate's house and his dad came in with Elvis' first album. From then on, all the lads were wearing blue suede shoes and growing sideburns. I've got every record he ever made.

"I grew up with an affinity for everything American. My mum used to collect American detective novels. So I grew up on Raymond Chandler and Erle Stanley Gardner. The English detective stories were all class-ridden so she hated them. All Agatha Christies are in big houses. The Americans always cut through the class bit."

In 1983 Bleasdale won the Royal Television Society Award as Writer of the Year for his series "The Boys from the Black Stuff," about the unemployed in England's impoverished north. Today he's hailed by people in the street who feel he speaks for them. Literary critic John Mortimer has called him "the most popular writer since Dickens."

"It's always the same thing, the sense that something is unfair, that drives me to the typewriter," Bleasdale said. His other works include "Having a Ball" -- set in a vasectomy clinic -- which he describes as "a play for women about male power," and a film comedy about old age and bigotry, called "No Surrender," to be released next year.

Bleasdale said he never had any intention of writing about Elvis Presley. "All my mates thought it was a pure act of lunacy for a working-class lad from Liverpool who's never been to America to write about the American Dream." He pauses. "But maybe you don't have to go there if you've always been there in spirit."