The constituency was defined as comprising 3 wards of the parish of Islington: Barnsbury, St Mary and St Peter.
These wards were used for the election of vestryman under the Metropolis Management Act 1855.
[1] Under the Representation of the People Act 1918 constituencies in the County of London were redefined in terms of the Metropolitan Boroughs created in 1900.
The constituency was defined as comprising three wards of the Metropolitan Borough of Islington having the same names as the previous wards: Barnsbury, St Mary and St Peter.
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; Notes References