Brycheiniog Tawe Nedd

A Senedd constituency comprising the boundaries of the UK Parliament constituencies of Brecon, Radnor and Cwm Tawe and Neath and Swansea East, has been proposed by the Democracy and Boundary Commission Cymru for the 2026 election to the Senedd (Welsh Parliament; Senedd Cymru). It was initially proposed using the English name Brecon, Radnor, Neath and Swansea East in September 2024,^[2] but was renamed to South Powys Tawe Neath and its Welsh name being De Powys Tawe Nedd, in December proposals, despite most other constituencies using Welsh-only names.^[3] It was later given the Welsh-only name Brycheiniog Tawe Nedd and its boundaries were confirmed in the commission's final recommendations in March 2025.^[4] When announcing their candidates, Reform UK used "Brecon, Radnor and Cwm Tawe, Neath and Swansea East" instead, using the English names for the pair of UK Parliament constituencies that form it.^[5]

It encompasses parts of the principal areas (counties/county boroughs) of Powys, Neath Port Talbot and Swansea in Mid and South Wales. The constituency is to be established by 2026, following the passing of the Senedd Cymru (Members and Elections) Act 2024. The act legislates electoral reform of the Senedd to create 16 larger "super constituencies", pairing the 32 UK Parliament constituencies in Wales, and using a new fully proportional voting system, with each constituency electing six Members of the Senedd (MSs) rather than one previously.^[2]