The borough has sent representatives to Parliament since the Model Parliament of 1295: two members were sent until 1885, when representation was reduced to one.
Boundaries
Colchester in Essex 1918-50
1918-1950: The Municipal Borough of Colchester, and the Rural District of Lexden and Winstree except the detached part of the civil parish of Inworth which was wholly surrounded by the civil parishes of Great Braxted and Kelvedon.
1950-1983: The Municipal Borough of Colchester, the Urban District of West Mersea, and the Rural District of Lexden and Winstree.
1997-2010: The Borough of Colchester wards of Berechurch, Castle, Harbour, Lexden, Mile End, New Town, Prettygate, St Andrew's, St Anne's, St John's, St Mary's, Shrub End, and Stanway.
2010–present: The Borough of Colchester wards of Berechurch, Castle, Christ Church, Harbour, Highwoods, Lexden, Mile End, New Town, Prettygate, St Andrew’s, St Anne’s, St John’s, and Shrub End.
Once the basis for one or two semi-rural seats, the modern-day Colchester constituency is a compact, urban core, containing the town centre and surrounding neighbourhoods.
The seat has one of Britain's largest residential military populations, but the non-military vote in Colchester has swung further in favour of the Liberal Democrats since 1997 when Bob Russell was elected for the party with a small majority. Russell increased both his total vote and percentage share in each of the succeeding elections. In the 2010 election it was the only non-Conservative seat in Essex. He was defeated in the 2015 general election by the Conservative candidate Will Quince, winning with a 11.5% majority. This made Clacton the only seat in Essex held by a non-Conservative MP as Douglas Carswell retained the constituency for UKIP having defected from the Conservatives the previous year.
In the 2017 election, Quince was re-elected with a slightly reduced 10.6% margin and increased tally of votes (5,677, 102 more than his 2015 margin), but the constituency saw a large 19.1% increase in the Labour vote, the first time Labour have come second in the modern Colchester seat and the first time they have done so in the area at all since 1979. This large improvement in Labour's performance may be linked to the party's manifesto pledge to abolish university tuition fees, a policy which may have attracted support from the student population of the nearby University of Essex, turning the seat into a genuine Tory-Labour marginal.
^Webster and Rebow were re-elected in 1714, but on petition the result was reversed and Gore declared to have been duly elected instead, following a dispute over whether foreigners could be made freemen of the borough and thereby acquire voting rights
^Webster was re-elected in 1710, but on petition the result was reversed and Gore and Corsellis declared to have been duly elected instead, following a further dispute over foreign freemen's voting rights
^At the election of 1741, Olmius and Martin were returned as elected, but on petition their election was declared void and their opponents, Savill and Gray, declared elected in their place
^At the election of 1754, Gray was re- elected, but on petition his election was declared void and his opponent, Rebow, declared elected in his place
^ abOn petition, Potter's election was declared void on the grounds of defective qualification and his opponent, Affleck, declared duly elected
Another General Election was required to take place before the end of 1940. 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;
Another General Election was required to take place before the end of 1915. The political parties had been making preparations for an election to take place and by the July 1914, the following candidates had been selected;
^Debrett's House of Commons & Judicial Bench, 1886
^Debrett's House of Commons & Judicial Bench, 1901
^Debrett's House of Commons & Judicial Bench, 1901
^Debrett's House of Commons & Judicial Bench, 1901
^Debrett's House of Commons & Judicial Bench, 1916
^Debrett's House of Commons & Judicial Bench, 1916
^‘GOLDFINCH, Sir Arthur Horne’, Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2016; online edn, Oxford University Press, 2014 ; online edn, April 2014 accessed 29 Nov 2016
Robert Beatson, "A Chronological Register of Both Houses of Parliament" (London: Longman, Hurst, Res & Orme, 1807) [1]
D Brunton & D H Pennington, Members of the Long Parliament (London: George Allen & Unwin, 1954)
Cobbett's Parliamentary history of England, from the Norman Conquest in 1066 to the year 1803 (London: Thomas Hansard, 1808) [2]
F W S Craig, "British Parliamentary Election Results 1832-1885" (2nd edition, Aldershot: Parliamentary Research Services, 1989)
J E Neale, The Elizabethan House of Commons (London: Jonathan Cape, 1949)
Henry Stooks Smith, The Parliaments of England from 1715 to 1847 (2nd edition, edited by FWS Craig - Chichester: Parliamentary Reference Publications, 1973)
