Former Vice President Al Gore and his wife of 40 years, Tipper, are separating, according to people close to the couple.

The Gores circulated an email Tuesday, notifying friends and associates that they'd made the "mutual and mutually supportive decision" after "a process of long and careful consideration."

No other reason was given for the separation other than they "grew apart" over the years. Friends also confirmed that no affair was involved.

"Their lives had gotten more and more separated," one associate -- who remained anonymous -- said.

During Al Gore's eight years as vice president, the pair painted an image of a happily married couple and famously exchanged a long kiss during the 2000 Democratic presidential convention.

Al Gore once said his wife was "someone I've loved with my whole heart since the night of my high school senior prom." Tipper Gore described her husband as "very much a gentleman" even when it came to small things like helping out around the house.

The Gores were married May 19, 1970 and have four adult children.