Plans for boundary changes could see the two Senedd constituencies in the Vale merged with neighbouring areas.

The first set of proposals from the Democracy and Boundary Commission in Wales suggests replacing the current system of 40 constituencies and five regions with 16 constituencies.

It forms part of wider Senedd reforms, which include increasing the number of members from 60 to 96.

The Vale of Glamorgan seat would be merged with Bridgend, while the Cardiff South and Penarth constituency would be paired up with Cardiff West.

A month-long public consultation on the boundary proposals is being held, with the commission expected to propose any alterations in December, before a final decision is made next March.

The new boundaries would take affect automatically at the next Senedd elections in 2026.

The Welsh Conservatives are opposing the wider Senedd reforms while the Electoral Reform Society (ERS) said significant change was "just around the corner for Welsh democracy".

Currently, Labour holds both Vale seats - with Jane Hutt representing the Vale since devolution began in 1999 and former First Minister, Vaughan Gething serving as MS for Cardiff South and Penarth since 2011.

The South Wales Central region - which includes the Vale - is represented by two Conservative MSs (Andrew RT Davies and Joel James), a Plaid Cymru MS (Heledd Fychan) and an independent MS (Rhys ab Owen), who was expelled from Plaid in July.

Under the proposals, each constituency would elect Senedd members using the D'Hondt system currently used for electing regional MSs.

The commission says it's had to create 16 constituencies by pairing up the 32 UK parliamentary constituencies representing Wales, ensuring that each constituency neighbours the one with which it its paired.

Shereen Williams, CEO of the Democracy and Boundary Commission Cymru, said: "Today marks a very important step in the journey towards reforming the Senedd."

"At the 2026 Senedd election, our national parliament will be elected using an entirely new system, with entirely new constituencies."

"The Commission is confident that our initial proposals represent a very good first step in creating Wales' 16 new Senedd constituencies, but we know from experience that these processes are always strengthened when we hear from the public."

"So we strongly encourage everyone to share their views with us, whether they support or oppose the proposals, so that we can go on to further strengthen the map ahead of the next election."

The full list of the initial proposed constituencies includes:

• Bangor Aberconwy Ynys Môn
• Clwyd
• Alyn, Deeside and Wrexham
• Dwyfor Meirionnydd, Montgomeryshire and Glyndŵr
• Ceredigion and Pembrokeshire
• Carmarthenshire
• Swansea West and Gower
• Brecon, Radnor, Neath and Swansea East
• Aberafan Maesteg, Rhondda and Ogmore
• Merthyr Tydfil, Aberdare and Pontypridd
• Blaenau Gwent, Rhymney and Caerphilly
• Monmouthshire and Torfaen
• Newport and Islwyn
• Cardiff East and North
• Cardiff West, South and Penarth
• Vale of Glamorgan and Bridgend

Key to the proposals, according to the Commission, is the belief that they should only be thought of as "contiguous" or neighbouring if its possible to travel throughout it without having to leave the boundaries.

The Commission says it has considered local ties, including shared history, the Welsh language and socio-economic links in an attempt to propose areas that "feel as natural as possible to people across Wales".

According to a report published on Tuesday, the Commission felt that merging the Vale of Glamorgan with Bridgend would be "uniting areas that have a shared sense of character" and have "good road links" between them.

Similarly, it felt there were "good road and communication links" between the Cardiff South & Penarth and Cardiff West constituencies.

Boundary changes at the general election in July saw Dinas Powys transferred from the Vale of Glamorgan to Cardiff South and Penarth - and as such, the town would be included in the paired Cardiff constituency, which also takes in the Pontyclun area of the Rhondda.

The Commission says it does not consider the impact of its proposals on future election results, but adds it is keen to understand whether there is public support for the proposals or whether residents feel their constituency should be paired with another.

It will also consider the proposed names of the constituencies.

Reacting to the plans, shadow constitution minister Darren Millar said the Welsh Conservatives "have consistently opposed Labour and Plaid's Senedd expansion proposals.

"it's the wrong priority and more boundary changes will cause yet further upheaval and confusion for those who have already had to contend with boundary changes in council and Westminster elections."

"We need a Welsh Government that is focussed on getting to grips with problems in our NHS, education system and economy, not one that is obsessed with more politicians and constitutional change."

Meanwhile, the Electoral Reform Society (ERS) in Wales have called for plans to introduce a closed list electoral system to be scrapped.

Jess Blair, director of ERS Cymru, said: "At the next elections in 2026 voters will be returning more members to represent them in new geographical areas under a new electoral system."

"Voters should be at the centre of these changes and it is welcome that the Commission is asking for the public's views on the proposed electoral map for Wales."

"Voters voices are the heart of any democracy, but they are currently at risk of being lost in the next election, due to the introduction of the Closed List electoral system, which only allows voters to back political parties rather than individual candidates."

"Ultimately to make these boundary changes work the best they can, the Senedd needs to move beyond closed lists after 2026."