The war-time electoral pact was an electoral pact established by the member parties of the UK coalition governments in the First World War, and re-established in the Second World War. Under the pact, in the event of a by-election only the party which previously held the seat would nominate a candidate, and the other coalition parties would stand aside. This led to a number of unopposed by-elections as well as strong showings and surprise victories by third party candidates.