Darkest Hour

(PG) ★★★★

Director: Joe Wright.

Cast: Gary Oldman, Kristin Scott Thomas, Ben Mendelsohn, Lily James, Ronald Pickup, Stephen Dillane, Samuel West.

Churchill was about to get very specific about which beaches they would fight on.

Just give Oldman the Oscar already. And while you're at it, give the best make-up Academy Award to Kazuhiro Tsuji.

No one else stands a chance in those categories against this colossal transformation. The fact Tsuji, lured from retirement for the task, makes Oldman look like a decent version of Winston Churchill is mindblowing. But it's Oldman's immersive turn that is the real brainbender. Never in its two hours does the film allow you to think anything other than "This is Churchill".

While it won't win the Oscar for best film (I'd like to see that honour go to Three Billboards Outside Ebbing, Missouri), this is still a wonderfully polished character piece, delivered with style by Wright.

To put it inelegantly, Darkest Hour is a prequel to fellow Oscar contender Dunkirk. As Hitler's army advances across Europe in the autumn of 1940, British parliament ousts Neville Chamberlain (Pickup) as prime minister, leading to the precarious and controversial appointment of Churchill as PM.

Within weeks of his promotion, Churchill is on the brink of overseeing the complete obliteration of his nation - the majority of the British army is trapped at Dunkirk, and unable to be evacuated by conventional means.

Darkest Hour provides an interesting viewpoint from which to examine the war. Very little in the way of battle is seen aside from some short eerie CG moments and a brief glimpse of the siege at Calais. Instead, we're treated to a behind-the-scenes look at WWII that basically involves lots of stuffy British pollies talking.

This dryness is offset by a number of things. Firstly, Wright's camera glides through the halls of parliament and the war bunkers with an engaging ease, helping ramp up the tension when necessary. Secondly, Dario Marianelli's score is used to help give scenes a nudge, preventing them from becoming too staid.

Thirdly, the script adds enough gentle humour and poetic licence to keep things ticking along nicely, hinging the "action" on several of Churchill's key speeches.

But really, it's Oldman that makes all the difference. Like the script, he doesn't strive for historical exactitude - listen to actual recordings of Churchill's "We shall fight on the beaches" and it's a world away from the fire and panache with which Oldman delivers it. It's rewriting history for the sake of drama, but the film is all the better for it, and the star is nothing short of convincing as he does it. Oldman is utterly believable whether suffering a bout of depression and a moment of doubt, or spitting vitriol in the war room, or gently sparring with Mendelsohn's King George VI. It's the greatest performance of an already great career.

Mendelsohn is also worth noting for his turn, as is James as Churchill's secretary (and audience surrogate) Elizabeth Layton, and Thomas as Churchill's put-upon but iron-willed wife Clementine.

Wright publicly mused whether people would be bothered to watch a film about Churchill, but rightly supposed they would watch one with Oldman playing Churchill. It's a masterstroke, and the film is a reminder of Wright's talents, particularly in the wake of his most recent film, the absolutely dire Pan.

Oldman should win his first Oscar for this performance - if he doesn't, something is wrong with the world.