Perhaps 6 years of doing the right thing for England started something for the media, a habit only destruction will break? ever since they have lied, it used to be you read the mail and the mirror and worked out the truth, the sun enabled Blair to bamboozle the public into supporting him wholesale, I stopped buying it then, shame I liked the crossword and page 3.
I am not at all sure that, during the war the media was doing the "right thing", per se. By and large, as always, the media had its own agenda, alongside the general objective of winning the war.
What is not clear from most of the histories you see written is that there was never any serious doubt that Britain (and the Empire) would win. Thus, throughout the whole period of 1939-45 there were two "wars" being played out ... the one to defeat Hitler, but the other to "win the peace" and determine the shape of post-war Britain.
It would be a mistake, therefore, to think that the people of the time were wholly focused on the shooting war, rallying behind Churchill in a common endeavour. They were not. The war was in many ways was seen as a portal, an opportunity for forging a new political settlement, with a huge amount of discussion and thought on that.
Different newspapers had different ideas, and - of those I have studied - the Mirror seems the most admirable ... writing with a degree of candour and honesty that was not seen elsewhere. That is why in October 1940, Churchill sought to have it closed down, and had to be dissuaded from trying to put a closure procedure into effect.
By and large, though, the newspapers were supporting the status quo - and especially Beaverbrook's Express. This was reflected in the way they presented the war. The lies, therefore, were in support not of the shooting war, but in the pursuit of the longer political agenda. That is as true today as it was then.