"A Private Function" is an amusing farce in the tradition of old Ealing studio comedies like "The Lavender Hill Mob," and like those movies, it never quite ignites.

As the film's opening newsreel tells us, Princess Elizabeth is about to marry Philip. Postwar rationing makes a proper celebration impossible, but the local burghers plan one anyway -- they're raising an "unlicensed pig" in contravention of the rules. Gilbert, a chiropodist (Michael Palin), angered by the snobbery of these small-town satraps and hungry for pork as well, spirits off the barnyard bounty. "It's not just pork, it's power," crows his wife (Maggie Smith).

The "private function" of the title stands for both the invitation-only wedding celebration and bathroom business, and the pun contains the germ of the movie's humor. "How ridiculous British airs are -- we're all animals!" says "A Private Function."

Screenwriter Alan Bennett, one of the founders of the influential "Beyond the Fringe" troupe that included Peter Cook and Dudley Moore, keeps the movie down in the dirt. The film's universe is filled with dead rats, chicken feet and the chiropodist's toenail clippings, which become the meal of the pig, which in turn gets munched beneath so many stiff upper lips. By the end, the people begin to resemble the pig, and the pig starts to look, well, human.

Bennett and director Malcolm Mowbray have some good fun with the chiropodist, who totes around a huge plaster foot (an emblem for his shop window) and exults at the dinner table: "Mrs. Park's ingrown toenail seems to have turned the corner." Palin plays him with pantomimic gestures so vivid and precise, he makes you wish they still made silent movies. He's as sweet as the Little Tramp, but like the greatest of the silent comedians, he can lash back when cornered.

And there's some sharp satire of social climbing, seated in Smith's brittle, British Blanche DuBois, who tells her husband, "My father wore a carnation in his buttonhole every day. I want a future that will live up to my past!"

The supporting cast is uniformly fine, including Liz Smith as Gilbert's senile mother-in-law, whose eyes roll in her head like a marble in a bowl; Denholm Elliott as Dr. Swaby, the nastily aristocratic town leader maddened by the onset of socialism; and Richard Griffiths, as the blubbery accountant Allardyce. And Bill Paterson is priceless as Wormold, the inspector from the Ministry of Food, impervious to the pleasures of the flesh since German measles left him without taste or smell.

John Du Prez's music masterfully evokes the movie's shifts in mood -- Wormold's leitmotif, for example, violin-sawing out of a cheap spy movie, mocks his job by inflating it (you'd think he was ferreting out state secrets instead of rump roasts).

But as well constructed as "A Private Function" is, it misses that touch of madness that Monty Python brought to the same comedic vein. Once you've seen a ton of man enter a restaurant, engorge himself and explode, watching a pig romp through a parlor doesn't seem enough.

A Private Function, at area theaters, is rated R and contains profanity, nudity and sexual themes.