| Middlesbrough (1983 - 2024) |
Seat of same name existed 1832-1918. |
| Milton Keynes South (2010 - 2024) |
This constituency (and its counterpart, Milton Keynes North), came into being when the two Milton Keynes constituencies (Milton Keynes North East and Milton Keynes South West) were reconfigured following the Boundary Commission's Fifth Periodic Review of Westminster constituencies |
| Mole Valley (1983 - 2024) |
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| Monmouth (1918 - 2024) |
Full name (in Craig 3,4) Monmouthshire, Monmouth |
| Montgomeryshire (1997 - 2024) |
Constituency of same name also existed 1832-1974ยน. |
| Moray (1983 - 2024) |
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| Morley and Outwood (2010 - 2024) |
Succeeds Morley and Rothwell. It consists of the town of Morley, in the City of Leeds metropolitan district, and around Outwood in the City of Wakefield district |
| Motherwell and Wishaw (1974 - 2024) |
Constituency first used at the February General election of 1974 (28/02/1974). |
| Neath (1918 - 2024) |
Full name (in Craig 3,4) Glamorganshire, Neath |
| Newcastle upon Tyne Central (1918 - 2024) |
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| Newcastle upon Tyne East (2010 - 2024) |
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| Newport West (1983 - 2024) |
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| Normanton, Pontefract and Castleford (2010 - 2024) |
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| Nottingham North (1955 - 2024) |
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| Ochil and South Perthshire (2005 - 2024) |
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| Ogmore (1918 - 2024) |
Full name (in Craig 3,4) Glamorganshire, Ogmore |
| Oldham West and Royton (1997 - 2024) |
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| Pendle (1983 - 2024) |
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| Penrith and The Border (1950 - 2024) |
Full name (in Craig 4) Cumberland, Penrith and the Border |
| Perth and North Perthshire (2005 - 2024) |
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| Preseli Pembrokeshire (1997 - 2024) |
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| Pudsey (1950 - 2024) |
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| Reading East (1983 - 2024) |
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| Reading West (1983 - 2024) |
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| Rhondda (1974 - 2024) |
Constituency first used at the February General election of 1974 (28/02/1974). Constituency of same name also existed 1885-1918. |