It was proposed following the 2026 review of Senedd constituencies, and will be a pairing of the two UK Parliament constituencies Dwyfor Meirionnydd and Montgomeryshire and Glyndà µr. It is to have a Welsh-only name.
A Senedd constituency comprising the boundaries of the UK Parliament constituencies of Dwyfor Meirionnydd and Montgomeryshire and Glyndà µr, has been proposed by the Democracy and Boundary Commission Cymru for the 2026 election to the Senedd (Welsh Parliament; ). It was initially proposed using the name Dwyfor Meirionnydd, Montgomeryshire and Glyndà µr in September 2024, but was renamed to in December proposals with most constituencies using Welsh-only names. The Welsh-only name and boundaries were confirmed in the commission's final recommendations in March 2025. When announcing their candidates, Reform UK used "Dwyfor Meirionnydd, Montgomeryshire and Glyndà µr" instead, using the English names for the pair of UK Parliament constituencies that form it.
It encompasses parts of the principal areas (counties/county boroughs) of Denbighshire, Gwynedd, Powys and Wrexham County Borough in North and Mid 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.