The cast also includes Kristin Scott Thomas as Clementine Churchill, Lily James as Elizabeth Layton, Stephen Dillane as Viscount Halifax, Ronald Pickup as Neville Chamberlain, and Ben Mendelsohn as King George VI.

[8][9] In May 1940, the opposition Labour Party in Parliament demand the resignation of British prime minister Neville Chamberlain for being too weak in the face of the Nazi onslaught.

Chamberlain chooses the only man whom the opposition will accept as leader of a national government: Winston Churchill, who had correctly predicted the danger from Adolf Hitler before the war but has a poor reputation in Parliament.

As Germany invades the Low Countries, Churchill is brusque with his new secretary Elizabeth Layton for mishearing him, which earns him a rebuke from his wife Clementine.

Churchill draws ire from his cabinet and advisers for delivering a radio address in which he falsely implies the Allies are advancing in France, earning him a rebuke from the king.

Against the advice of the War Cabinet, Churchill orders Brigadier Nicholson in Calais to lead the 30th Infantry Brigade to distract the enemy and buy time for the evacuation of soldiers from Dunkirk.

Still uncertain, Churchill impulsively rides the London Underground (for the first time in his life) and asks startled passengers their opinions; they all want to continue to fight Hitler.

A textual epilogue reveals that almost all the soldiers trapped at Dunkirk were successfully evacuated; Chamberlain died six months later; Halifax was reassigned to a posting in Washington, D.C., and Churchill was voted out of office shortly after the end of World War II in Europe.

On 5 February 2015, it was announced that Working Title Films had acquired Darkest Hour, a speculative screenplay by The Theory of Everything screenwriter Anthony McCarten, about Winston Churchill in the early days of the Second World War.

[12] On 6 September 2016, it was announced that Focus Features would release the film in the United States on 24 November 2017, while Ben Mendelsohn was set to play King George VI and Kristin Scott Thomas was cast as Clementine Churchill.

[21] Filming also took place at Warner Bros Leavesden Studios in Hertfordshire for the scene where Churchill gets onto the London Underground, with a 1959 stock train hired from Mangapps Railway Museum in Essex.

[30] Peter Travers of Rolling Stone wrote: "Get busy engraving Oldman's name on an Oscar... those fearing that Darkest Hour is nothing but a dull tableau of blowhard stuffed shirts will be relieved to know that they're in for a lively, provocative historical drama that runs on its own nonstop creative fire".

[31] David Ehrlich of IndieWire praised Wright's direction and the musical score, writing: "Unfolding with the clockwork precision of a Broadway play... it's a deliciously unsubtle testament to the power of words and their infinite capacity to inspire".

[32] Damon Wise of the Radio Times described the film as a "near-perfect companion piece" to Dunkirk, concluding: "Wright's forceful direction depicts not so much a hero as a principled man snatching victory from the jaws of defeat.

[38] There is no conclusive evidence that Chamberlain and Viscount Halifax were planning an imminent vote of no confidence, though that threat existed until the mid-war victories in North Africa.

[40] Adam Gopnik wrote for The New Yorker that Darkest Hour "badly underdramatized" the role of Labour Party leader Clement Attlee; historically, "it was the steadfast anti-Nazism of Attlee and his Labour colleagues that saved the day" when Halifax argued for negotiating a settlement, but Darkest Hour failed to accurately portray this and was a "Churchill-centric" film, Gopnik argued.

"[43] Hirsch also criticised the film for "perpetuating the idea that Winston Churchill stood alone at the Darkest Hour, as Nazi fascism encroached, with Britain a small and vulnerable nation isolated in the north Atlantic.

In reality, the United Kingdom was at that moment an imperial power with the collective might of Indian, African, Canadian and Australian manpower, resources and wealth at its disposal.

[47] Oldman stated in February 2018 that there was talk of making a sequel to Darkest Hour that might include Franklin D. Roosevelt and take place in 1945 during the Yalta Conference.