Dunkirk strengthened the British resolve to defeat Nazism in the face of overwhelming odds. But it did so only after an eloquent and charismatic speaker, Winston Churchill, reframed the event for the public.

'Wartime Winston' wasn't the globally-adored icon that he became towards the end of his life. As the movie Dunkirk screens to acclaim, it's the story behind the narrative which inspires the inner patriot in me.

Director Christopher Nolan has attempted to show all sides to the massive rescue effort, including the role played by civilian boats, some of which came from Norfolk. More than 300,000 British and Allied troops had been cut off and surrounded by the German army. They stood on the shores of Dunkirk in desperate need of rescue. The stories of heroism are incomparable; however, Mr Churchill's political stoicism has been underplayed.

At 3.40pm on June 4 1940, Churchill strode into the Commons with his characteristic determined look. His demeanour didn't portray the stresses of a few days where Britain's sovereignty was in peril or the burden of responsibility on his shoulders. His sanitised account of events on the French coast wouldn't pollute the treasured national perception of 'invincible' Britannia, but was much more gritty than what the public was previously used to. A radio announcer read the speech to the public that night (Churchill himself didn't narrate an audio recording until years later). Winston retired to his office expecting a backlash.

His speeches are credited with having galvanised the nation sowing the seeds of the ultimate victory. But many academics agree that the impact of his wartime addresses have been vastly overstated. Professor Richard Toye challenges the accepted view that the speeches were received enthusiastically fuelling the nation's willingness to fight on against Hitler. Rather, he claims, the works generated controversy and criticism. Many listeners even believed Churchill was drunk or 'muddled' when he talked in public.

This is a far cry from how popular history remembers our 'greatest-ever' leader.

As a huge admirer of Winston, I'm keen to highlight the truth. It increases my appreciation of his ability to plough on. His dogged determination, fostered in early life, called upon in 'The Wilderness Years' was, in war, a national asset. Far from the compliant and adoring reception many believe he received, Churchill fought some of his fiercest battles in the 'domestic theatre of war'. He was passionately disliked. Mocked. Often undermined.

Churchill's speeches have become part of a treasured national myth, which has obscured the fact that they often caused disappointment and criticism at the time. The ambiguous response to Churchill's operations helps to explain his subsequent defeat in the 1945 General Election.

This heroic tale of 'the little ships' typifies the wonderful spirit which help turn the tide of war in Britain's favour. It is a story that from childhood, to this very day makes me proud of our country. But politically this was a masterpiece in public relations. The spin was a necessary deception.

Churchill described the 'miracle of deliverance' from Dunkirk and warned of an impending invasion. He steered away from the unpalatable truth. His words transformed Dunkirk into a symbol of British courage. His speech was a paradox; though his assessment appeared brutal, he left the listener with hope. It was exactly what the nation needed to hear to galvanise our fight against Hitler. He needed to ignite our fighting spirit.

The virtue of hindsight affords Churchill a favourable critique of his speeches. The prominence of Second World War history offers Churchill a reprieve when considering his extensive failures, from Gallipoli to putting Britain back onto the gold standard, he frequently demonstrated poor judgement. But this is why I adore him: he was often wrong, but he was the right man at the right time.

His Achilles' heel was stubbornness - but it also turned out to be his greatest strength.