LAST autumn, you didn't need much in the way of perception or acumen to see the connections between the film of the moment – Christopher Nolan's Dunkirk – and the moment itself, in particular the efforts of the embattled British government to extricate the country from the European Union without leaving all the valuable bits on a beach somewhere on the French side.

Those connections didn't favour the government either. The evacuation of the British Army at Dunkirk in May 1940 has been parlayed into a heroic folk tale in which victory is snatched from the jaws of defeat. But with David Davis cast as a sort of modern-day Captain Mainwaring by many Leave voters, the Brexit negotiations are fast being parlayed into Dunkirk's mirror opposite – defeat snatched from the jaws of apparent victory.

However, if the government thought there was no more where that came from once the year had turned they were wrong. The biggest film of 2018 is set to be another historical drama about Britons in extremis in which Europe once again looms large, and which once again makes for a withering compare-and-contrast exercise between its central character – a certain cigar-smoking Prime Minister with a penchant for V-signs and eccentric headwear – and the politicians who currently have the keys to Downing Street.

The film is Darkest Hour. Released in the UK on Friday, it's the story of Winston Churchill's fateful first month in power after he was raised to the position of Prime Minister on May 10, 1940, the day the German invasion of France began. Directed by Joe Wright, it stars Gary Oldman as Churchill and the chameleon-like actor is now being spoken of as a strong contender for an Oscar. He's already won one award for the role, picking up an accolade from Peter Fonda last Tuesday at the Palm Springs Film Festival. Last month he was also nominated for a Golden Globe.

Churchill isn't the first historical figure Oldman has played. In 1986 Alex Cox handed him the role of Sex Pistols bassist Sid Vicious in Sid And Nancy, and a year later Stephen Frears cast him as anti-authoritarian playwright Joe Orton in Prick Up Your Ears. Four years on again, Oldman was mesmerising as Lee Harvey Oswald in Oliver Stone's 1991 Kennedy assassination conspiracy thriller, JFK.

It isn't even the first time Oldman has been offered the role of Winston Churchill, having previously turned down the part. “I had always been fascinated by Churchill as he was truly our greatest statesman, yet he wasn’t someone that I was looking to play,” Oldman has said. “In fact, the prospect of playing him had come my way years ago and I’d rejected the idea … It wasn’t the psychological or the intellectual challenge that was the hurdle, it was the physical component. I mean, you need only look at me and look at Churchill.”

Prosthetics and make-up have rectified that problem in Darkest Hour. But Vicious, Orton and Oswald were all outsiders. Winston Churchill, though often characterised as a rogue element within the British political establishment, is hardly that. Described by historian and former keeper of the Churchill Archive Centre Piers Brendon as “a potent cross between English aristocracy and American plutocracy”, Churchill was born to money, power and influence. Aged 12, he watched his own father, Lord Randolph Churchill, become Chancellor of the Exchequer. Aged 14 he entered Harrow School, which had already produced six Prime Ministers. He completed his education (if that's the right word for it) at Sandhurst, where Britain's military elites are trained. He later served in the army (with the |Fourth Hussars and then the Scots Fusiliers) before working as a journalist and finally entering parliament. In many ways Churchill was establishment to the soles of his patent leather Oxfords. To prove the point, it's said he always had his valet tie his laces for him.

So Oldman is walking in the shoes of a very different sort of historical figure to the ones he has previously portrayed. How different can be seen by the number of books that have been written about Churchill (the current estimate is 1,000). Or the number of films and television programmes in which he features (Brian Cox played him on screen as recently as last year – “You don't get many better roles than Winston Churchill,” he said – and John Lithgow currently plays him in Netflix hit The Crown). Or the general esteem in which he is still held today, over 50 years after his death.

In short, Churchill is a bona fide National Treasure. So much so that when the BBC launched a wide-ranging poll in 2002 to try to find out who people thought were the greatest ever Britons, it was him who came out top, ahead of Darwin, Shakespeare, Newton and, yes, even then-Prime Minister Tony Blair (67th on the list, would you believe?).

A decade later, in front of 80,000 people in the Olympic stadium, and with many millions more watching on television, the closing ceremony of the London Olympics featured another actor, Timothy Spall, emerging from a model of Big Ben dressed as Churchill to perform Caliban's famous speech from Shakespeare's The Tempest: “Be not afeard: the isle is full of noises”. Once again you didn't need much in the way of acumen to join the dots: Danny Boyle's brilliant opening and closing “Isles Of Wonder” ceremonies had also hymned the NHS, lollipop ladies, Britain's free press tradition, the Industrial Revolution, the women's suffrage movement, The Beatles and punk rock, and its overall themes were bravery, defiance, humour, innovation and a stubborn belief in democracy. How could it not also feature a cigar-toting Winston Churchill as the embodiment of those principles?

Of all of those things it's defiance and bravery which lie at the heart of Churchill's appeal. When he took office in May 1940, there was a significant school of thought among his parliamentary colleagues that the UK should sue for peace with Hitler, who was then poised to invade the UK. Churchill was of the opposite opinion. In one of Darkest Hour's pivotal scenes, he takes to the Underground to ask Londoners what they think. They're resolutely in favour of standing firm against the Germans and continuing the war.

“The question was whether to fight on alone, perhaps to the destruction of the armed forces and even the nation, or to play it safe as Viscount Halifax and [outgoing] Prime Minister Neville Chamberlain believed,” says Darkest Hour screenwriter Anthony McCarten, who centred his script on three important speeches Churchill delivered between May and June 1940. “Winston had to wade into this fray, and he found himself battling the Establishment … This story is anchored in the past yet it resonates all the way into the here and now. Too often today, our ‘leaders’ are followers. These decisions made in less than one month’s time had global ramifications.

“Words can, and do, change the world,” he adds. “This is precisely what happened through Winston Churchill in 1940. He was under intense political and personal pressure, yet he was spurred to such heights in so few days, over and over again.”

However, McCarten says he also wanted “to push the boundaries” of the public's understanding of Churchill, to move beyond the historic speeches, the Greatest Ever Briton tag and the image of the man as some sort of mythical hero. “With regard to Churchill, I feel his three-dimensional nature had become buried under a veneer of history,” he says. “The more famous a historical figure is, the greater the sense of public ownership in them. Winston’s weaknesses, foibles, and doubts have been airbrushed out of even the most thorough biographies. He’s now often portrayed as this completely resolute character. I think we do him more justice when we present him warts-and-all. In the last 10 years scholarship is starting to reveal other dimensions, so Darkest Hour is part of that new school of thinking.”

All of which begs the question: is the popularly held view of Churchill as a brave and defiant hero the correct one? Or are there, in fact, a multiplicity of Churchills to fit any and all political and historical viewpoints? And with the UK once again divided over Europe and how to act towards it, who can claim to have the real Churchill on their side of the argument?

The answer seems to be everyone. So on the one hand you can have Boris Johnson – also half-American, also a former journalist, also a political renegade with a populist touch – penning of a book about Churchill in 2015 which offered up parallels between subject and author so unsubtle that even The Spectator magazine had to ask: “Does Boris Johnson really expect us to think he's Churchill?” (More on that: referring to a passage in the book in which Johnson writes about Churchill putting his shirt on “a horse called anti-Nazism” and “the bet coming off in spectacular fashion”, the Financial Times's Gideon Rachman retorted “I thought of that passage when I heard that Johnson has thrown in his lot with the Leave campaign … Mr Johnson has put his shirt on a horse called Euroscepticism. He is clearly hoping that his bet will also 'come off in spectacular fashion' and carry him, like Churchill, all the way into 10 Downing Street.” It still might, of course.)

On the other hand, you have the opinion of Gary Oldman himself, who last week told Spanish newspaper El Mundo about Darkest Hour's modern “political reading” and added: “Churchill would not have allowed Brexit. In any case, he would agree with those who oppose it … Let's not forget that he was PM thanks to the support of the liberals, since he caused great divisions among Conservatives. His idea was of the United States of Europe, although his vision was something different from the economic union that was born with time.”

That point about the film's modern political reading isn't lost on either of the film's co-producers, Lisa Bruce and long-time Oldman collaborator Douglas Urbanski. “When Eric Fellner [head of Working Title films] began to bring people together to discuss the project, we realised that this would be a journey worth taking, a movie that would entertain people – but also make them stop and think about the resonance of history,” says Urbanski.

“Darkest Hour is timely because we feel a void of leadership now,” adds Bruce. “We want someone to rise to the occasion as Winston did.” The implication, of course, is that nobody currently is rising to the occasion in a properly Churchillian sort of way – nor is anyone among the current crop of British politicians likely to do so in the immediate future.

That might be an uncomfortable thought for those in government who do think they have a smidgen of the Churchillian about them, or who do subscribe to the “Cometh the hour, cometh the man” theory of history (or, in these non-gendered and diversity-friendly times, the woman). But perhaps that “void of leadership” has its upside. In his book Winston Churchill: A Brief Life, Piers Brendon talks about his subject's “monstrous compound” of courage, energy, tenacity, volatility, egotism and brutality, and says Churchill “always saw himself through the basilisk eye of history, as a man of destiny bestriding his narrow age like a colossus ... so powerful was his personality, so compelling his eloquence, that he managed to make others share his glittering vision”.

Eloquence aside, that almost sounds like a description of Donald Trump, nobody's idea of a good leader. In any case it's not exactly the description of a stable personality, is it? Besides, we aren't actually at war and (though Brexiteers would disagree) we aren't at risk of being invaded either. So perhaps our bumbling British politicians and slick European technocrats are more appropriate actors for the matters at hand than the irascible iconoclast with the cigar in one hand and the glass of Scotch in the other. Perhaps we just need to leave Winston Churchill to his time and his place, and get on with the present.

Darkest Hour is released on Friday