1918–1983: The Urban Districts of Bridgend, Maesteg, Ogmore and Garw, as well as a part of the Rural District of Penybont.
1983–2010: The Borough of Ogwr wards of Bettws, Blackmill, Blaengarw, Caerau, Llangeinor, Llangynwyd, Maesteg East, Maesteg West, Nantyffyllon, Nant-y-moel, Ogmore Vale, Pencoed, Pontycymmer, St Bride's Minor, and Ynysawdre, and the Borough of Taff-Ely wards of Brynna, Gilfach Goch, Llanharan, and Llanharry.
2010–2024: The Bridgend County Borough electoral divisions of Aberkenfig, Bettws, Blackmill, Blaengarw, Bryncethin, Bryncoch, Caerau, Cefn Cribwr, Felindre, Hendre, Llangeinor, Llangynwyd, Maesteg East, Maesteg West, Nant-y-moel, Ogmore Vale, Penprysg, Pontycymmer, Sarn, and Ynysawdre, and those in Rhondda Cynon Taff County Borough of Brynna, Gilfach Goch, Llanharan, and Llanharry.
A substantial change of boundaries took effect in 1983, when the new constituency of Bridgend was created, centred on the town of that name, which was by then the largest settlement in Ogmore. The constituency since that date consisted of the northern part of the original constituency, together with wards from the former Borough of Taff-Ely (now Rhondda Cynon Taf CBC).
History
Summary of winning results
The 2015 result made the seat the 44th-safest of Labour's 232 seats by percentage of majority.[3] Successive candidates fielded by the Labour Party have won absolute majorities (pluralities) since the seat was created in 1918, or have run unopposed four times. The 2019 election was the first time in the seat's 101-year history that Labour failed to win an absolute majority, though the party still won with a margin of 22%
Opposition parties
Four parties have taken the runner-up position from and including a 2002 by-election, a total of five elections. At the 2015 general election the Liberal Democrat, Green and TUSC candidates did not win 5% of the vote apiece therefore forfeited their deposits. Those running for the Conservatives and UKIP in 2015 (and 2016 at the by-election held during the month before the UK's EU membership referendum) held their deposits. The highest polling of any runner-up, by percentage, was Thomas George Jones in 1931, winning 30.8% of the votes cast, 0.3% more than half the percentage polled by the winning candidate; this was when the Labour Party's vote was slightly split by the presence of a prominent Communist Party candidate and editor, Johnny Campbell. The government's dropping of a prosecution against him in 1924 had led to a General Election.
Turnout
Turnout at general elections has ranged between 85.3% in 1950 and 57.8% in 2005, falling to 35.2% in the 2002 by-election.
^ abcdefghijCraig, F. W. S. (1969). British parliamentary election results 1918-1949 (1 ed.). Glasgow: Political Reference Publications. ISBN0-900178-019. p. 561
^ abcdefgCraig, F. W. S. (1971). British parliamentary election results 1950–1970 (1 ed.). Chichester: Political Reference Publications. ISBN9780900178023. Page 581
^"Politics Resources". Election February 1974. Politics Resources. 28 February 1974. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
^"Politics Resources". Election October 1974. Politics Resources. 10 October 1974. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
^"Politics Resources". Election 1979. Politics Resources. 3 May 1979. Archived from the original on 11 August 2011. Retrieved 2 February 2021.
Craig, F. W. S. (1983) [1969]. British parliamentary election results 1918-1949 (3rd ed.). Chichester: Parliamentary Research Services. ISBN0-900178-06-X.