Colchester is a constituency[n 1] in Essex represented in the House of Commons of the UK Parliament since 2024 by Pam Cox, of the Labour party.

[2] Once the basis for one or two semi-rural seats, the modern-day Colchester constituency is a compact, urban core, containing the city centre and surrounding neighbourhoods.

In the 2017 election Quince was re-elected by a slightly decreased margin by percentage (10.6%), with Labour moving into 2nd place after a substantial increase in their vote.

The seat lost the ward of Old Heath and The Hythe in the 2023 Boundary Commission review but despite this, Colchester was won by Labour for the first time since 1945 in the 2024 United Kingdom general election with Pam Cox as the new MP.

The political parties had been making preparations for an election to take place from 1939 and by the end of this year, the following candidates had been selected; Trotter's death a caused a by-election.

The political parties had been making preparations for an election to take place and by July 1914, the following candidates had been selected; Smyth's resignation caused a by-election.