Northampton (UK Parliament constituency)

A former MP of note for the constituency was Spencer Perceval, the only British Prime Minister to be assassinated.

Vernon Smith was appointed Secretary of State for War, requiring a by-election.

Bradlaugh was unseated after voting in the Commons before taking the Oath of Allegiance, causing a by-election.

[18] Bradlaugh was expelled from the House of Commons due to his continuing prevention from taking the Oath, causing a by-election.

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;