This, oddly, is the second film in the Cannes competition about the Nazi occupation of France, and it is more interesting than László Nemes’s rather mainstream drama Moulin – a complex, ambiguous study of national humiliation from writer-director Emmanuel Marre. He has created an absorbingly intimate, novelistically detailed procedural about the day-to-day, moment-by-moment lives of the Vichy administrators after the fall of France, mostly shot conventionally, sometimes jolting into an anachronistic dreamlike scenario on video.

It is centred on the director’s own great-grandfather Henri Marre, who held a minor but important post in the Vichy ministry of labour. The film is in fact unsparing of this conceited, petty, but weirdly sensitive and vulnerable man: Swann Arlaud plays him as a sociopathic mixture of haughty idealist, salon intellectual and conman predator, a man who doesn’t really believe in anything but his own survival and has only the vaguest idea about what such survival could mean.

The film follows Marre and the Vichy pen-pushers in almost real time as they busy themselves with what appear to them innocuous administrative tasks. But at frog-boiling speed, they gradually realise that what they are required to do is organise the transportation of the Jews, a project originally called ramassage (or “roundup”) but coyly renamed by Marre and the Vichy ministers rassemblement (or “collective relocation”). We witness a bureaucratic row about the excessive cost involved in providing Jews on cattle trucks with straw and chamber pots.

The Vichy apparatchiks are delusional and avoidant, grimly seizing on the idea of salvaging some martyred patriotic survival from the catastrophe of the Nazi invasion, building a new France as reactionary and antisemitic as the Germans. This is partly to cauterise the mortification and partly to appease the Nazis into continuing to allow this supposed “free zone” in the south under the poignantly defanged leadership of first world war hero Marshal Pétain.

Marre is shown appearing in this Vichy France out of nowhere, all but penniless, a slippery but plausible entrepreneur who has already squandered almost all of his wife’s family fortune and that of his trusting investors in his various doomed schemes. He has his left his wife and children behind and the film quotes his wife’s angry – and presumably genuine – letters to him in voiceover. Now he sees France’s catastrophe as a way of reinventing himself as a national visionary, brandishing copies of his self-published manifesto for national renewal, paid for by his wife, entitled Notre Salut (or Our Salvation).

Marre wheedles his way into Vichy soirees and embarrasses his hosts with his indiscreet contempt for the Nazis and the misjudged excess of his Pétain hero-worship. Like a petitioner in tsarist Russia, Marre hangs around ministerial offices hoping for a job, and sycophantically endears himself to one senior figure by rescuing the man’s beloved cat from behind the demarcation zone – a farcically undignified and dangerous task.

But once in employment, Marre instantly demonstrates his instinctive flair for the middle-management leadership style and maudlin patriotic Pétain-worship, supervising the hanging of a huge mural about France’s new mission. He busies himself with all manner of little tasks, ostensibly to see how costs can be cut, but really because this kind of immersion is how he imposes his own power and curates his own undistinguished career. He schools members of the public in how to shout pro-Pétain slogans, and auditions secretaries from the dozens of applicants, whimsically choosing the laziest and least competent, perhaps so that this personal assistant will never get above herself or show him up. His elegant wife Paulette (Sandrine Blancke) joins him with their children in a handsome new apartment which used to belong to a Jewish family.

But with a terrible inevitability, he realises that Vichy France’s supposed independence is a sham, and his notional responsibility for forced labour is overruled by the Germans’ chilling Organisation Todt. The Germans become more and more insistent on the antisemitic roundups and Marre’s own superiors become increasingly panicky and shrill in their demands that he simply gets on with the business of obeying. Finally, as D-day dawns, we are to see Marre reverting to type, buying up abandoned businesses with government cash and keeping back for himself a larcenous “commission”, a pathetic and lonely figure, deserted by his family and everyone else.

Marre’s film gives a very shrewd, painful account of what Marcel Ophüls’ film called the sorrow and the pity: what the Vichy administrators felt was self-pity and a kind of doomy sorrow at their own misfortune. Arlaud gives an excellent performance as an intelligent, talented man who almost, but not quite, realises the terrible swamp into which he has descended.