SENEDD: The seats Wales voted in for the first time in May are already being redrawn, and the names could change too

Four months after Wales voted in them for the first time, the 16 Senedd constituencies are being redrawn.

The Democracy and Boundary Commission Cymru launched its 2030 review this week, with the new map taking effect at the next Senedd election and initial proposals due in early 2027.

The seats across Swansea Bay and Carmarthenshire, Gŵyr Abertawe, Brycheiniog Tawe Nedd, Sir Gaerfyrddin and Afan Ogwr Rhondda among them, were built for May’s election by pairing Westminster constituencies, two at a time. That rule has now gone.

In its place comes an electoral quota. The commission says every constituency must sit within 10% of the Welsh average, which works out at 150,128 electors on the December 2025 register, so each of the 16 seats must contain between 135,225 and 165,275 voters.

The commission will also weigh council boundaries, geography and local ties in drawing the lines, and is required to keep changes to a minimum.

The names are in play too. Under the rules, constituencies should carry a single-language name unless the commission considers that unacceptable, and it is the commission that decides what each seat is called.

May’s vote was the biggest shake-up of Senedd elections since devolution: 96 members instead of 60, six elected in each constituency from closed party lists under the D’Hondt system, and turnout above 50% for the first time.

It produced a Senedd transformed, with Plaid Cymru on 43 seats, Reform UK on 34 and Labour cut to nine, and 66 of the 96 members new to the institution, Mike Hedges the only Swansea Labour MS returned.

The review cannot touch any of that. The commission says it is unable to consider representations about the number of members or the voting system, so the consultation is about lines and names, not the system behind them, a debate Hedges has already demanded, calling the new voting system one that “does not work”.

What the public can shape is the map. An eight-week consultation follows the initial proposals in early 2027, with public hearings and any revised proposals to come after, and final determinations going to Welsh ministers before 1 December 2028.

Shereen Williams, the commission’s chief executive, said: “The Commission is looking forward to holding a full review for the Senedd’s constituencies, with a greater opportunity for people to share their views and impact the proposals.

“Whenever the Commission holds a review, the public’s feedback, especially on their local area, is vital to making sure our determinations are the strongest possible.

“The move from pairing parliamentary constituencies to using an electoral quota does mean that some changes will be necessary at this review, but it also gives us an opportunity to respond with greater flexibility to the public’s views, while ensuring that we minimise changes wherever we can.”

Responses will go through the commission’s online portal, by email or by post once the consultation opens, with full details published alongside the initial proposals, and more at dbcc.gov.wales.

The map Wales voted on in May, in other words, was the temporary one. The permanent version gets drawn over the next two years, and this time the public helps hold the pen.