So this movie had the bad fortune to come out near-simultaneously with Darkest Hour, another historical movie about wartime Winston Churchill, nominated for six Oscars, winning two (including Best Actor).
And this movie was nominated for zero Oscars, winning zero. Oh well.
Brian Cox plays the man, and I guess he does a decent job of acting. The time period covered is early June, 1944, the lead-up to D-Day. Ike shows up in the person of John Slattery. Miranda Richardson plays wife Jennie.
The problem that kills this movie is that it is (apparently) nearly completely divorced from historic fact. Churchill is painted as an ardent opponent of the Allied invasion plans, insisting on a broader attack front, coupled with diversionary strikes in the Aegean and Norway. (He's haunted by the WWI disaster at Gallipoli, you see.) He is a constant incompetent thorn in the side of Ike and Monty. When his efforts to influence the invasion plans are thwarted, driven by vanity and guilt, he demands to go into the battle himself, taking the King along as well.
And, finally, when that's vetoed, he prays—literally, on his knees—that God send bad weather in order that the invasion be called off.
None of this happened. See, for example, Andrew Roberts' review, documenting that the flick "gets absolutely everything wrong".
I'll give it 1.5 stars for getting something right: Churchill did, apparently, smoke cigars and drink a lot.