See eg:
This is British interwar history, as told by the makers of The King's Speech. And it's bunk. No one would know from this scene, or any of the others in which the two appear, that Churchill had supported, lobbied for Edward VIII's right to wed Mrs Simpson and stay on the throne, that for most of the Thirties he was regarded by the establishment as a crazy, washed-up has-been, and that George VI would go on to become a staunch supporter of Chamberlain's policy of appeasement.
http://www.newstatesman.com/blogs/cultural-capital/2011/01/king-speech-churchill-filmWinston Churchill is the crucial figure here. As you may have read you will get no hint from the movie that Churchill – the only British politician of the period whom most audiences remember – did himself immense political harm by backing Edward VIII and Mrs Simpson against Stanley Baldwin's government's insistence that they could not marry and retain the throne.
Baldwin was right, as he usually was in his tussles with Churchill in the 20s and 30s – think the General Strike of 1926, think the Indian independence question – but even on the one where he was wrong the facts are pointlessly distorted so that he is presented as conceding that "Churchill was right" as early as 1937 when he hands over to Neville Chamberlain.
...
Far from being a Churchillian, the king didn't like him. Why should he after the abdication fiasco? Even in 1940 he would have preferred Halifax as PM. Mistrust with the palace was mutual. They had all known each other for decades and, according to Andrew Roberts's book, Eminent Churchillians, Churchill thought George V pretty stupid too.
George VI backed Chamberlain to the point of breaking with protocol and allowing his prime minister to appear with him on the balcony of Buckingham Palace after Munich, having been persuaded not to go and meet him at Heston airport. In the film the scene of waving crowds in the Mall is transposed to September 1939 – hardly likely with German air raids already underway.
http://www.guardian.co.uk/politics/blog/2011/jan/17/kings-speech-looking-back-time-didnt-exist