The third and final George Clooney movie of this year’s Times BFI London Film Festival is one of the most mature works of the actor’s credible and increasingly complex career. He stars as Ryan Bingham, a white-collar hatchet man who specialises in corporate lay-offs and criss-crosses the United States for 322 days of the year, racking up nearly 10 million air miles and ruining the lives of shell-shocked workers with a disingenuous speech about the bright side of being fired. Here, in repeated sequences that are timely and subtly affecting, the director Jason Reitman assembles montages of non-actors — all real-life victims of corporate downsizing — who react to this devastating news with a mixture of disbelief, despair and anger (presumably as they did in real life).

The recession-era message, however, isn’t overlaboured. Instead, from a breezy script by Reitman and Sheldon Turner (adapted from a novel by Walter Kim), the emphasis is increasingly placed on classic screwball comedy rather than social realism. Thus Bingham, in an hotel bar, runs up against his female counterpart, Alex (Vera Farmiga), a fellow corporate shark who lives for air miles, executive perks and the comforting anaemia of a business-class existence. The two, naturally, become an item, and a fabulously droll post-coital scene pictures the pair in underwear, laptops out, coolly scanning schedules for future windows of romantic opportunity.

Together, Alex and Bingham, like the best screwball couples (think Hepburn and Grant) banter brusquely, and there is a suggestion of healthy suspicion and professional competition beneath their encounters. Yet a certain longing in Bingham’s eyes hints that this might be the one human encounter that wakes him from his soulless corporate coma.

The fly in the ointment? A young twentysomething company hotshot called Natalie (played by Anna Kendrick) whose money-saving schemes threaten to ground Bingham completely and swap his frequent-flyer lifestyle for a videophone and an internet link in a striplight office in downtown Omaha.

Reitman, as he showed in his previous Oscar-winning smash Juno, has a deft touch when it comes to pulling comedy performances from assorted acting talent. And, typically, the cast of Up in the Air is filled with generously rounded support — Farmiga, especially, is a standout as a clear-eyed seductress.

But this is Clooney’s movie. Yes, for much of the time he does the familiar silver-haired fox routine, espousing his “no commitments” lifestyle with a convincing dreamy-eyed smile. But there is a certain aching sadness that permeates his entire performance, and that is only fully realised in the film’s final act, suggesting deeply satisfying and hitherto unexplored depths in Clooney’s range. He weights profoundly the entire movie, and it is this performance — above anything else he has delivered this year — that will be recognised at Oscar time.

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