NASHVILLE, TENNESSEE?Former US Vice President and current anti-global warming campaigner Al Gore once claimed his romance with wife Tipper inspired the novel ?Love Story.?

The couple also shared an uncomfortably long kiss before millions on the stage of the 2000 Democratic National Convention.

Now, after a 40-year marriage that survived the near-death of a child and the heartache of losing the disputed 2000 presidential election, the former high school sweethearts are calling it quits.

The Nobel Peace Prize laureate who has been touring the globe to push the theme of climate protection, Gore, 62, is scheduled to present in Manila on June 8 an updated version of his acclaimed 2006 documentary ?An Inconvenient Truth.? He delivered a similar lecture in Manila four years ago.

?After a great deal of thought and discussion, we have decided to separate,? the Gores wrote in an e-mail to friends on Tuesday. ?This is very much a mutual and mutually supportive decision that we have made together.?

Growing apart

The Gores told friends they ?grew apart? after four decades of marriage and there was no affair involved, according to two longtime close associates and family friends.

The couple had carved out separate lives over time, with Gore on the road frequently, said the associates, who spoke on condition of anonymity because they were not authorized to speak on the couple?s behalf.

?Their lives had gotten more and more separated,? one of the friends said.

The couple, who own homes in Nashville and Gore?s hometown of Carthage, Tennessee, had reportedly purchased an $8.8-million estate in Montecito, California, this spring.

Married on May 19, 1970, at National Cathedral in Washington, the Gores crafted an image of a happy couple during his 8-year stint as vice president in the 1990s and a presidential candidate in 2000.

Contrast to Clintons

Their warm relationship stood in sharp contrast to the Clinton marriage that was rocked by Bill Clinton?s affair with White House intern Monica Lewinsky, a scandal that hung over Gore?s own presidential campaign.

At the time, Gore said his wife was ?someone I?ve loved with my whole heart since the night of my high school senior prom.? Then, as if to prove it, he planted that long, awkward kiss on her during the 2000 Democratic presidential convention.

The embrace, though derided by some as choreographed, helped bring home Gore?s message that he was ?my own man.? Such public affection did much to enliven the former vice president?s stuffy image.

Flirting within bounds

Mary Elizabeth ?Tipper? Gore, 61, painted a picture of a playful relationship, saying in a 2000 interview with The Associated Press that she teased her husband while he prepared for presidential debates by e-mailing him ?lascivious? messages.

?He e-mails me back and says, ?I?m losing my concentration now,?? she said.

?He?s a little bit more of a gregarious flirt than people would realize?all within bounds,? she added.

In a speech to the 2004 Democratic convention, Gore said he wanted to thank ?with all my heart my children and grandchildren, and especially my beloved partner in life, Tipper.?

The ?Love Story? claim came in 1997, when Gore told a reporter he and Tipper were the inspiration for Erich Segal?s 1970s best-seller.

A surprised Segal said that Gore, whom he knew at Harvard, had inspired one side of his male hero?s personality?the one controlled by a domineering father?but his book had nothing to do with Tipper Gore.

Son?s drug rehab

In a letter written to then-girlfriend Tipper as a 17-year-old college freshman, Al Gore hinted at that dynamic. ?Mother?s having a fit about me riding the motorcycle back to Harvard. Dad?s mad at my long hair,? he wrote.

The Gores have four children, Karenna, Kristin, Sarah and Albert III, all now adults. Their son underwent rehab treatment in 2007 after marijuana and prescription drugs were found in his car when he was pulled over for driving 160 kph in his Toyota Prius.
Gore was Clinton?s vice president from January 1993 to January 2001, and fought a bitter battle over disputed November 2000 election results in Florida before conceding to George W. Bush.

After losing the 2000 presidential election, Gore turned his attention to climate change, undertaking a worldwide campaign which led in 2007 to a Nobel Peace Prize and an Oscar for the documentary ?An Inconvenient Truth.?

Life as VP spouse

The couple were married about six months when Gore was deployed to Vietnam as an Army public information officer.

When he got home, he landed a job as a reporter at The Tennessean in Nashville, and his wife worked there as a photographer. Tipper later chronicled her life as the vice president?s spouse as well as Gore?s 2000 presidential campaign.

In the 1980s, she was active in trying to get record companies to put warning labels on their records about profane lyrics. The campaign resulted in record labels attaching ?Parental Advisory? stickers to music with adult language.

The effort, however, drew widespread criticism from musicians and civil liberties activists, who decried what they saw as censorship.

Tipper also won praise for her work as an advocate for mental health issues.

Punishing schedule

Gore later served in his father?s former seats in Congress for 16 years.

Determined to avoid pitfalls that snared his father, who was accused of being out of touch, Gore kept a punishing schedule, traveling home to Tennessee for open meetings three weekends a month?and leaving wife Tipper alone in Washington with their four young children.

Gore first ran for president in 1988 at age 39 but drew little support outside the South. A planned bid for the 1992 nomination was put aside after the Gores? 6-year-old son Albert III almost died after being hit by a car in 1989.

?It was a very spiritual time for both of us,? Tipper Gore later wrote. ?In Al?s case, he decided to write a book and not to run for president in 1992.?

Light-hearted couple

The book was ?Earth in the Balance,? and Al Gore ended up in the thick of the 1992 campaign anyway?as Bill Clinton?s running mate.

In Washington, the Gores were a power couple?with a light-hearted touch. On Halloween, they would dress in costumes to greet trick-or-treaters at the vice president?s mansion. One year she was a puppy and he was dressed as Underdog.

In the 2000 campaign interview, Tipper acknowledged Al had his faults. He once gave her a Weedeater for her birthday, but he learned to be more sensitive over the years, she said.

A gentleman

?He?s very much a gentleman you know, with me around the house,? Tipper said. ?I know he?s dog tired and he could be sitting down and doing something and I need something across the room, he?ll get up and get it.?