Finsbury in the Parliamentary County of London, 1918–50
It was originally proposed that the constituency would comprise the entire Finsbury Division and a number of adjoining parishes in the Holborn Division of Ossulstone, one of the hundreds of Middlesex. The commissioners appointed under the Boundaries Act decided to exclude the northern part of the Finsbury Division, which extended as far as Friern Barnet, some nine miles from London and a largely rural area. They could find no natural boundary to separate "the Rural from the Town District" and suggested that the dividing line should run through the northern section of Islington, following the boundaries formed for Church of England ecclesiastical districts. The seat as eventually created included the whole of Islington, however.
The parliamentary borough was defined in Schedule O of the Boundaries Act as:
Another General Election was required to take place before the end of 1940. The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;