One week, three days and nine hours. That was the length of time between the start of the first Cannes showing of Cristian Mungiu’s Four Months, Three Weeks and Two Days and the film winning the Palme d’Or. The time it took me to push a microphone at him after seeing the film, journalists being more rapid-response than juries, was one day, one hour and one minute.

What could not be measured in any unit was the delight we Cannes-goers experienced at a worthy film winning the top prize. This happens about as often as a solar eclipse and is as dangerous to witness. The mind is seared by excess effulgence; the eyes can melt like lemon drops in the sun.

The state of Mungiu’s mind is hard to guess. Three weeks ago he was an unknown Romanian with an unheralded movie featuring unheard-of actors. Now he is up there with Coppola, Polanski, the Coens and company as recipient of the top festival’s frond embrace.

Full-faced, fast-spoken (in English) and younger-looking than his 39 years, he was in a Cannes beach bar when I spoke to him, wearing a white shirt and being bombarded by the first advance troops of the fourth estate.

What is happening out there in Romania, I ask? The country wins the Palme d’Or this year. Two years ago with The Death of Mr Lazarescu and this year with California Dreamin’ it comes top in the non-competitive sideshow “Un Certain Regard”. (In Cannes even non-competitions have prizes.) What are Bucharest directors eating for breakfast?

“We share a way of seeing cinema. We have this focus on telling a story with a certain kind of realism and directness. I try to stay with the storyline” – in this film’s case a harrowing tale of illegal abortion in the last years of Ceausescu – “and not have my message throw out the reality of the characters. I think this is in common with The Death of Mr Lazarescu.”

Lazarescu, made by Cristi Puiu, went straight round the world, powered by the pitiless candour of its chronicle of a dying man being shuttled between hospitals. The film, brilliantly made, was like looking at a naked lightbulb for three hours. Mungiu’s film is shorter but no less unremitting.

“The story came from a girl I knew who was involved in an abortion. I was affected very much because it was someone close to me. I realised the story had all the ingredients – all the bitterness – for a film about that period for people of my generation.”

Those people are of course “Ceausescu’s children”, Romanians who came of age under Communism, then experienced the miracle of its collapse.

“I conceived the project of which Four Months is part, and for which other films are planned, as a history of late Communist times. Personal stories, urban legends. Like other directors my age, I have the distance now to talk about things that affected me when I was 20.”

Distance, joined to a kind of nightmare immediacy. Almost every scene is filmed in one take with no cuts or close-ups.

“I don’t prepare my shots beforehand. I go on set and say, ‘This is the space, this is the dialogue, let’s do it as fluently as possible.’ I want the script to sound totally natural. I write it aurally, phonetically, dropping words or letters, the way people talk. I choose actors who can memorise 10 pages of dialogue so I don’t have to cut. I want the story to come straight to the viewer without sensing there is a filmmaker.”

This would be a grim recipe for a commercial film. But Four Weeks, Three Weeks and Two Days is hardly that. Who put up the money?

“Most of it came from the state or state-incentive sources. There’s a national screenwriting competition, which if you win you get enough money for half your budget.” (Mungiu did.) “There are also levies from TV or advertising which go into feature production.”

The new Romania is probably happy to throw money at films that dig the Ceasescu era into a deep grave.

“But I don’t think that trend will continue,” Mungiu says. “The good thing that has happened already is that our vision is different from the films shot immediately after 1989. Those were full of anger and little else. They were made by people less attentive to cinema than to their political beliefs and grievances.”

The breadth of Mungiu’s own background helps to explain the breadth of his movie. It’s not just about Communism or abortion; it’s about the hope that fights its way out of despair, the moral catastrophes that purge and enlighten. He started as a newspaper journalist, when that trade’s practitioners were regarded as near-messiahs.

“When the revolution came, we were seen as people bringing the truth. We were stopped on the street and given cigarettes or something to eat.” He then worked in radio and TV. Later he had a spell as a professor of language and literature.

I ask if Romania itself, and Romanian cinema, will be broadened by the country’s new membership of the European Union.

“I hope it will make a difference, but it won’t happen overnight. There are people who believe that becoming formally part of Europe is enough and we will all immediately be integrated. But a big effort is needed. The good thing is that Romanians who are not very educated and come to work here” – he gives a vague, sweeping gesture to indicate France and western Europe – “understand things a little better than if they stayed home and read newspapers. People can’t really be educated in schools. You come here to see how others live and behave, and you go back a different person. Things will change, little by little, person by person.”

More Nigel Andrews