[4] Hampstead lay within the area of the Metropolitan Board of Works, and in 1889 this became the County of London.
[4] Parliamentary constituencies were redrawn under the Representation of the People Act 1918, with boundaries in London realigned to those of the metropolitan boroughs.
Accordingly, the Hampstead constituency was defined by the legislation as being identical in area to the metropolitan borough of the same name.
The renamed Hampstead Borough Constituency continued with the same boundaries, with the changes coming into effect for the 1950 general election.
The constituency was officially renamed "Camden, Hampstead Borough Constituency" and was defined as comprising seven wards of the London Borough, namely Adelaide, Belsize, Hampstead Town, Kilburn, Priory, Swiss Cottage and West End.