The Big Blockade is a 1942 British blackandwhite war propaganda film in the style of dramatised documentary. It is directed by Charles Frend and stars Will Hay, Leslie Banks, Michael Redgrave and John Mills. It was produced by Michael Balcon for Ealing Studios, in collaboration with the Ministry of Economic Warfare.
The film premiered at the London Pavilion onJanuary 1942, and the premiere was attended by a group of members of Parliament interested in economic warfare. The film was not very well received by The Times critic in 1942, who found that this particular hotchpotch is, as propaganda, woefully unconvincing. It is splendid to give audiences a glimpse of the devoted work done by the Services but actors got up as comic Nazi business men distort the lessons the more serious parts of the film are trying to drive home, and modern film reviewers are not very much kinder to it.
Source: Wikipedia