"A PRIVATE FUNCTION," a repugnant, scatological satire, stars Michael Palin as a cheery chiropodist and Maggie Smith as his socially aggressive wife. No function other than a banquet for the future Queen is held private or sacred in this body-obsessed British farce.

Though well-performed and beautifully produced, "Function" is still a movie about a pig with the "squits." And its anal fixation makes you wonder if writer Alan Bennett didn't have a very bad time of it during his toilet training years.

Bennett's screenplay is set in post-war England, when food is rationed and black market laws are strictly enforced. A juicy chop will bribe a cop and a pound of bacon is better than a pound of flesh.

In Yorkshire, the butcher consequently rises to the top of a threadbare social order led by the town doctor (Denholm Elliott), the barrister (John Normington) and the accountant (Richard Griffiths), who are planning a pork roast to celebrate Princess Elizabeth's marriage to Philip Mountbatten. They are, of course, like swine themselves, greedy, beady- eyed and, in one case, fatter than the unlicensed pig they have bribed a farmer to fatten for the feast.

Betty, the porcine protagonist, is discovered by Palin, our chiropodist, while tending the farmer's wife's bunions. Her toenail clippings, rats, cling peaches, Spam and the newspaper wrapping holding it are all fed to Betty who comes down with a long, loud case of diarrhea in a tiresome climax that finds the chiropodist and his wife with the pig in their parlor and an improved place in the social order. Sort of a Pig-malion.

This is a film of wrinkled noses, and we are lucky, I suppose, that odorama has been left behind as a cinematic viability. Director Malcolm Mowbray's work is extremely realistic, even adroit, but it's also gross. And is it really socially enlightening? How a nation treats its pigs may be meaningful, but it always pays to remember that you can't make a silk purse of a sow's rear.

A PRIVATE FUNCTION (R) -- At the Circle MacArthur.