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Revised Boundary Changes: Seats to Watch

Fergus Turtle
Fergus Turtle

The House of Commons is undergoing a boundary review and last week the Boundary Commission for Wales released its revised proposals. These will reduce Wales’ constituencies from 40 to 32 to reflect its proportion of the UK’s population, as per The Parliamentary Constituencies Act 2020. The new proposals make some significant changes to the first proposals released last year and are considerably different to the current map. So, what are the political implications?

The abolishment of 8 constituencies means that there will be several intense selection fights to get on the ballot paper. These would include:

Pembrokeshire: this will likely be an internal election between two former Conservative Welsh Secretaries, Simon Hart and Stephen Crabb. Hart may be more likely to win a selection contest for South Pembrokeshire. Alternatively, Hart might contest the new Carmarthen constituency or Crabb Ceredigion Preseli, but these will be much harder to win in an election.

Seats in Swansea and Neath: Labour could see an internal battle here; we will have to see whether Christina Rees’ current suspension means that a selection battle in one of the new Swansea seats will be avoided.

Bridgend: Bridgend constituency’s removal from the map (the new ‘Bridgend’ seat is based on the current Ogmore seat) means Jamie Wallis will not have a winnable seat. Whilst he may stand against Labour’s Chris Elmore for the new seat, the changes make it more likely that Labour will retain the seat.

South Central valleys: the new Pontypridd seat encompasses much of the current Cynon Valley seat, possibly meaning a selection contest between Labour’s Beth Winter and Alex Davies-Jones. This could be a tough contest with Winter popular among Labour’s left and Davies-Jones carrying the advantage of being a Shadow Minister. [UPDATE: Beth Winter ran for selection in the new Merthyr Tydfil and Upper Cynon seat and lost to Shadow Wales Minister Gerald Jones]

Newport West and Islwyn: Sitting Newport West MP Ruth Jones could continue as the Labour candidate in the new seat with sitting Islwyn MP Chris Evans potentially standing in the new Caerphilly seat if Wayne David stands down as expected. However, this will likely be a difficult battle with plenty of local Caerphilly Labour Members likely having their own interest.

Wrexham and Montgomeryshire: Simon Baynes will either have to fight it out with Sarah Atherton or Craig Williams to win selection to be the Conservative candidate in the new Wrexham or Montgomeryshire and Glyndwr seats. The latter would likely be a tougher selection contest but also is much more likely to return a Conservative MP.

Delyn: Rob Roberts’ suspension from the Conservatives due to sexual harassment would likely give Vale of Clwyd MP James Davies a clear run to be the Conservative candidate for the new Delyn seat.

Gwynedd Seats: Hywel Williams would either have to challenge Liz Saville-Roberts to become Plaid’s candidate for an expanded Dwyfor Meirionnydd or attempt to win the expanded Aberconwy for Plaid, which looks like a pretty tough ask.

In terms of implications for parties, current proposals are likely to make the map less competitive:


The Conservatives would automatically lose a seat in the southwest and in Bridgend as well as two in the northeast. The changes do potentially make it easier for them to hold some of their remaining seats. In the northeast, most of these are likely to be lost to Labour despite this, given current polling trends. Proposed changes to the Vale of Glamorgan, a classic Tory-Labour bellwether and seat of former Welsh Secretary Alun Cairns, would make it harder for the Conservatives to hold.

Plaid Cymru would lose one seat in Arfon but could offset this with a gain in Ynys Môn where they have high hopes. Aberconwy’s boundary changes could move this seat into play for them, but they are a distant third in the current seat. The new Ceredigion Preseli and Carmarthen seats present better security for Plaid than the initial proposals, as the revised proposals expand these new seats to take in some stronger Plaid areas. However, the revised proposals also limit further their opportunities for expansion, notably in Llanelli.

Labour would lose two of their 2019 seats. Furthermore, the proposed map substantially reduces their potential for gains in Wales: partially an inevitable consequence of Wales’ loss of seats.

The inclusion of more of the upper Swansea valley in Brecon and Radnorshire could make the seat more winnable for the Liberal Democrats if the area’s traditionally Labour voters are inclined to vote tactically. 

As it stands the likely changes mean an overall reduction of 8 seats. Based on recent results, this would likely mean that the Conservatives lose around 4 seats, Labour 3 and Plaid Cymru 1 seat.

The current opinion polling, however, suggests the next General Election in Wales would lead to significant losses of seats for the Conservatives. The new boundaries could seriously limit how much Labour gain from this. A reasonable best-case scenario could put around 6 gains on the map for Labour under the revised boundaries. Under the current boundaries, they could pick up as many as 10 or 11.

Essentially, however Wales’ new boundaries finally end up being drawn, the reduction in seats almost certainly will hurt Labour more than the Conservatives in the long term due to Wales being an area of Labour strength. This is true of a number of other traditionally Labour-voting parts of the UK which is partly why the Conservatives are keen to get the plan over the line.


As of 28 06 23 the final proposals have been published. These are largely the same as the revised proposals with a small number of noteable differences. 

Bridgend and Ogmore: the new Bridgend seat looks a lot more like the current Bridgend seat, with the current Ogmore seat being split between three new constituencies. This is better for the Conservatives than the revised proposals though it will still make it harder for them to retain it than under current boundaries. 

Swansea and Gower: the new Gower seat has been extended to include a number of areas previously included in the proposed new Swansea West seat. These changes will likely make the seat marginally more competitive for the Conservatives.

Caerphilly and Islwyn: the new Caerphilly seat has gained the Ynysddu area from the neighbouring Newport West and Islwyn. This will likely not have a major impact on who can win the seat. 

Dwyfor Meirionydd and Montogmeryshire: the final proposals for Dwyfor Meirionydd take in some additional areas which were designated for the new Montogomeryshire and Glyndwr constituency. This will likely make Dwyfor Meirionydd an even safer seat for Plaid Cymru and harder for the conservatives to be challenged in Montogomeryshire and Glyndwr.

Overall, these changes seem to be moderately good news for the Conservatives but do not substantially change the electoral prospects for any party, especially if current polling is accurate.

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

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