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The Proposed Parliamentary Boundary Changes in Wales

The Boundary Commission for Wales has undertaken a review of parliamentary constituencies in Wales. This follows the review of English constituencies which was published back in June and precedes forthcoming reviews in Scotland and Northern Ireland. The discussions over boundary changes started back in 2012 under the Conservative-Liberal Democrat coalition government but were blocked by the Lib Dems and then Theresa May’s government didn’t pick them up. However, the cards are now back on the table and up for discussion.

The review seeks to even out the number of constituents that each MP represents. Currently there are some seats with much fewer electors than others. Added to this, the size of constituencies in Wales has historically been lower than elsewhere in the UK – this review will change that. As a result of these changes Wales will go from having 40 MPs to 32 with all seats (apart from Ynys Môn) having around 73,000 electors.

The big changes to note

The last time we had a major discussion on redrawing the boundaries of Welsh seats and reducing the number of Welsh MPs was in 2016. The proposals we see now are quite different to those suggested only five years ago, which would have seen Labour lose the most seats. The political make up of Wales at Westminster had a huge shake up in the 2019 General Election resulting in more seats that are represented by a Conservative MP and Labour constituency MS than ever before. With our current political map these proposals suggest more limited damage to Labour with the injury shared across the parties.


The biggest changes for Labour are (unsurprisingly) in south-central to south east Wales. The changes to the Cardiff seats all look to benefit Labour, strengthening their hold on Wales’ capital city. However, some of the smaller valleys seats, such as Cynon Valley, disappear as they are swallowed by neighbouring constituencies. As Islwyn brings in almost 15,000 more electors, Merthyr Tydfil joins up with Aberdare and Rhymney joins with Blaenau Gwent there is likely to be a fierce contest between the current MPs for these areas to represent these new, bigger constituencies.

The biggest factor at play for Labour in this review is not that seats they currently hold will be at risk of swinging to another party due to boundary changes, but that the number of seats in South Wales drops overall. The review’s proposals look like they will lose around three sitting members, meaning the party will need to pick up seats outside of their South Wales strongholds if they are to mount a serious Westminster challenge.


The changes proposed by the review suggest that the current and a previous Secretary of State for Wales will see big changes. Carmarthen West and South Pembrokeshire will take in parts of Preseli Pembrokeshire, losing its north east flank to Carmarthen East and Dinefwr. The Pembrokeshire seats have been strong for the Conservatives so this loss, along with the new make-up, creates an opportunity for Labour in the west.

The Welsh “red wall” seats that fell to the Conservatives in 2019 will also be a concern with the shake-up of boundaries in the north east resulting in a drop in the number of seats. This is problematic for the Conservatives as their recent success means they have more to lose. To the east of Aberconwy the number of seats drops from six to four, and with five of the six currently held by the Conservatives they will lose at least one seat in the north. It will be critical for Labour to take these seats back if they are to stand a chance of getting back into government at Westminster.

Bridgend was the only seat in south Wales to switch to the Conservatives in the last general election but as the constituency would be changed significantly under these proposals, the Tories would almost definitely lose the seat making the total loss three.

Plaid Cymru

Arfon, a key Plaid Cymru seat, could go as it is divided up and ‘given’ to Dwyfor Meirionnydd and Aberconwy. Although Plaid have tried to mount a challenge for Aberconwy at a Senedd level, their support in general elections has been very low making it a poor prospect.

It is likely that Plaid will hold Dwyfor Meirionnydd and the redrawn Ceredigion Preseli, therefore other than the loss of Arfon, Plaid Cymru look unlikely to be otherwise disadvantaged by the review, losing only one of their four seats. However, there are few changes which open up genuine opportunities for the party to take a serious challenge to constituencies held by either Labour or the Conservatives.

It is worth noting that Ynys Môn has “protected status” meaning there are no changes to its boundaries, and it is left with just over 52,000 electors. The constituency has a rather colourful history having been held by Plaid, Labour and the Conservatives in the last three general elections.

What next?

These are parliamentary proposals relating to the number of MPs. Although the Senedd would have the option to adopt them if it wanted to, it has no obligation to do so, and if it did it would raise the long-debated question about the number of Senedd Members – an article for another day.

The Commission has stated that these proposals are “to start the conversation” and the proposed map is not a done deal. But whatever the conversation, as is often the case in politics, it is very unlikely that any change would make everyone happy.

For a bird's eye view.
Am olwg oddi uchod.

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