Poldark villain and Hammer Horror stalwart Ralph Bates was brilliantly cast against type as the crumpled and hapless title character.
The sitcom concerns itself with a middle aged man starting his life again after discovering his wife has left him.
Having to find himself lodgings (with an amusing foreign landlady, of course) John decides to widen his social circle by attending a singles club.
The 1-2-1 Club is presided over by the fruity Louise, whose stock question to any new recruit is (with relish) "Were there any sexual problems?"
John's fellow attendees include the bespectacled, greasy haired and geeky Ralph (Peter Denyer wringing laughs and sympathy in equal measure); the flamboyant and boastful Kirk St Moritz, resplendent in white suit, big collars and medallion; the attractive Kate, whose past experiences have made her guarded and cynical and the willowy Sylvia.
John Sullivan's knack for character and the poignant central conceit of the loneliness of middle-age, ensured that despite only a short run, the series made a decent impact.
Gradually the assorted misfits make bonds and forge ahead with their lives, being mutually supportive despite their differences.
In one typical flourish of Sullivan genius, when John visits the overweening Kirk, he's revealed to be a cardigan wearing recluse called Eric.
John persuades him that he'd be welcomed by the group as the real him, rather than the cocky persona he has assumed, but at the end of the episode, it is of course Kirk, not Eric, who appears.
Bates was superb at displaying a knack for downtrodden comedy and pathos, but John proved to be his last major TV role before his early death from cancer.
Dear John was adapted for US television (with Taxi's Judd Hirsch in the title role) and prospered longer than its UK progenitor.
