Representatives of the clergy recently outraged at "Monty Python's Life of Brian" were no doubt sincerely vexed at the movie's sophomoric impieties. But the outrage may be setting up gullible customers for a big letdown.

To put it as gently as possible: There's never been a really hilarious comedy shot on location in Tunisia; perhaps it was too much to expect that even the Python gang could break such a jinx.

Instead of turning on the righteous indignation, it might be more charitable, and more of a public service, to let this labored, cheerless Biblical or historical or costume or whatever-it-was-supposed-to-be farce sink of its own ponderous weight and feeble humorous defenses. It's a cruel fiction to foster the delusion that "Brian" is bristling with blasphemous nifties and throbbing with impious wit. If only it were! One might find it easier to keep from nodding off.

The title leads one to expect a satiric gloss on the "Life of Christ," but the troupe evidently lacked the nerve or inspiration to follow through. The plot begins with the Three Wise Men blundering into the wrong stable, where they discover the infant Brian and his abrasive Cockney Mum (played by Terry Jones, who also serves as the director).

The visitors proceed to worship Brian and leave their gifts with Mum. Before long they discover their error -- the real holy child is located in a neighboring manger, clearly recognizable by its neon-bright halations -- and retrieve their presents from Brian's miffed ma.

Graham Chapman assumes the role of the grown Brian, discovered hovering on the outskirts of the crowd as Jesus delivers The Sermon on the Mount. His incorrigible mother prefers to attend a stoning, so the scene shifts to a facetious stoning where women wearing false beards let loose whenever anyone says "Jehovah." No, it doesn't play especially funny either. Maybe you had to be in Tunisia.

Jesus slips out of the continuity. Brian, his obscure contemporary, never manages to pick up the slack, although he's auditioned as both a political dupe and religious leader. His infatuation with a girl terrorist lures Brian into a blowhard revolutionary group called the Judean People's Front. Trying to duck the Roman constabulary, he murmurs a few suggestive platitudes in public and accidentally attracts a loyal following.

Never a commanding figure, Brian too drops out of sight for considerable periods, to be replaced by John Cleese as a stolid centurion trying to ferret out subversives or Michael Palin as a Pontius Pilate who talks like Elmer Fudd.

Palin has a dynamic turn as a vanity-ridden, servile prisoner chained to a dungeon wall, and there's a smartly written passage during a cell meeting of the JPF when the group ends up sourly acknowledging that their Roman masters are also their betters. A totally gratuitous interlude sends Brian up in a UFO with two wild-driving monsters. Slowly, the whole meandering enterprise muddles toward the musical finale -- a smugly cheerful ditty for crucifixion victims -- and the mercifully expires.

Some of these gags may sound better than they play, but even the ones with playing power lack staying power. The scenario has so little structural cohesion that even if a funny bit emerges, it tends to evaporate quickly, leaving no afterglow or promise of sustained amusement.

"Life of Brian" is a marginal improvement on "Jabberwocky" (anything would be), but it has fewer highs and less energy than "Holy Grail" or "And Now for Something Completely Different," the revue-style film that introduced the Python group to movie customers. Of course, all these vehicles put together might have fewer surefire laughs than "The Concorde -- Airport '79," but why rub it in?

The troupe probably needs to drop costume-movie farce for the time being. The comic returns seem to be diminishing the further they recede into ancient history. It's all too easy to imagine them struggling to squeeze a few gags out of the Old Testament or prehistoric times, but if anything, the time has come for a reversion to modern dress.

Perhaps they also should abandon the pretense of sustaining a feature-length story continuity, since it merely emphasizes the miscellaneous nature of the sequences. It's easier to shake off weak or misfired sketches in a revue format. When you're led to expect some dramatic progression, the weak stretches can be lethal.

"Life of Brian" seems about 95 percent weak stretches, which is tantamount to suicide. There's an amusing title song, torched by Shirley Bassey (or a slick impressionist) in Bond-movie style, and Terry Gilliam's animated credits are fluid and witty.

But the troupe continues the bad habit of coming on with too many production "values" -- elaborate period settings and costumes, fussy composition, multiple roles for everyone -- at the expense of a sustained satiric focus and strong comedy material.