The Big Blockade was a 1942 British black-and-white war propaganda film in the style of dramatised documentary. It was directed by Charles Frend and starred 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.^[1][2][3]

At one stage, the film was known as Siege.^[4]

This was a propaganda film in which the British strategy of the economic blockade of Nazi Germany was illustrated through a series of scenes and sketches, combined with documentary footage.

Although released in 1942 it was largely made in 1941 so part of the story is complaint of America's non-involvement.

The film's commentary is made by the journalist and former Liberal MP Frank Owen.

The film premiered at the London Pavilion on 19 January 1942, and the premiere was attended by a group of members of Parliament interested in economic warfare.^[5] The film was not well received by The Times, whose critic in 1942 found that "this particular hotch-potch 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",^[6] and modern film reviewers are not very much kinder to it.^[7]