‘The Party’ a tense tale from superb a director

Assembling a dinner party is a bit like putting together a meal: The ingredients need to be the right proportion.

In Sally Potter’s delicious new black comedy “The Party,” the acclaimed English filmmaker deliberately flouts such convention, gathering a cast of smart, veteran character actors — each one embodying a different set of values — and setting them in conflicts that obliterate the line between the political and the personal. This is a film that encapsulates the anxiety of the moment, complicated by friendships that lean, at times, toward hostility.

As the film opens, congratulations are in order: Janet (Kristin Scott Thomas), a member of an unnamed opposition party under the U.K.’s Tory government, has just been named shadow health minister. As she prepares a small meal to celebrate with friends, her erratic husband, Bill (Timothy Spall), gets drunk and listens to records.

Janet’s guests — each of whom seems to have some secret — include April (Patricia Clarkson), a cynic who can’t hide her contempt for her New Age boyfriend, Gottlieb (Bruno Ganz); and Tom (Cillian Murphy), who arrives with a pistol and a stash of cocaine. As for Janet, she clutches her BlackBerry, texting her lover. Inevitably, bitter confrontations ensue, as the dinner guests find themselves rethinking their core beliefs.

Potter’s black-and-white cinematography (a format she has not used since 1997’s “The Tango Lesson”) recalls the tradition of such classic dinner-party-from-hell tales as “The Exterminating Angel” and “Who’s Afraid of Virginia Woolf?” With the absence of color, viewers can better focus on individual, finely tuned performances. Although the action never leaves Janet’s house or backyard, the camera is always dynamic, framing the actors in unconventional shots that are halfway between letting the actors breathe and claustrophobic.

The dialogue — literate without feeling overwritten — begins with an exchange of compliments that devolves into gentle jokes, then mean-spirited ones and finally outright arguments.

In addition to Janet’s big news, there are more big announcements coming: Jinny (Emily Mortimer) is having triplets with her partner, Martha (Cherry Jones), while Bill drops a bombshell that is downright shocking.

To the extent that “The Party” has a fault, it lies in Potter’s affection for her characters. Too often, she lets them off the hook, abandoning the exaggeration common to satire. Potter’s cast never overstays its welcome, giving us plenty to think — and talk — about, and in a scant 71 minutes.