Changes to constituency boundaries in Wales will see number of Welsh MPs cut by eight
Wales' constituency boundaries could be significantly redrawn before the next general election under plans to reduce the number of Welsh MPs.
Voters are being asked to share their views on the proposals from the Boundary Commission for Wales in an eight-week consultation on how the boundaries could be changed.
It follows confirmation earlier this year that the number of parliamentary representatives in Wales will fall by eight, from 40 to 32.
The reduction represents the "most significant change to Wales's constituencies in a century", the Commission said.
The new constituencies are due to come into force at the next general election.
Tory peer and polling expert Lord Hayward predicted they could result in two or three Tory losses, three or four Labour losses, and Plaid Cymru losing either one or two seats.
Members of public are now being encouraged to set out whether they support or oppose the proposals.
The Commission said that, if adopted, they would "result in a Parliamentary map of Wales very different from the one we are familiar with".
But it warned it could not consider arguments over the number of constituencies as it has no power to set the number of MPs, which was decided by Parliament.
Boundary changes are also taking place in England, Scotland and Northern Ireland in order to reflect population changes across the UK.
Overall, the Conservative Party is set to gain 10 seats in the restructure.
Under the Parliamentary Constituencies Act 1986 (as amended), each nation and region of the UK is given a share of 650 MPs based on the number of registered electors.
The Act also says that each constituency must contain between 69,724 and 77,062 voters, 5% either way of the UK average.
There is one exception to this rule in Wales - Ynys Mon can remain outside of the statutory range.
Other than this constituency, boundary changes are proposed for all others in Wales, the Commission said.
Some constituencies see changed names under the proposals, while some are fully absorbed into neighbouring constituencies.
Commenting on his predictions, Lord Hayward said: "Two seats are particularly close to call, they are Carmarthen and Alyn and Deeside."
He added that for the Conservatives and Labour "inevitably both parties face the possibility that two MPs of the same party will have to face off against each other because of the reduction of seats in Wales".
He said for the Tories this would be in Pembrokeshire/Carmarthen and North-East Wales, while for Labour it could be in Mid Glamorgan, Gwent and around Swansea.
The Commission said it had taken into account geographical features, such as lakes, rivers and mountains, when shaping its proposals, and also considered "local ties", such as "shared history and culture."
It explained that under its initial proposals six principal councils would be wholly contained within new constituencies (Blaenau Gwent, Ceredigion, the Isle of Anglesey, Merthyr Tydfil, Monmouthshire and Torfaen).
Some 16 existing constituencies would be wholly contained within new constituencies under the proposals (Aberconwy, Alyn and Deeside, Blaenau Gwent, Brecon and Radnorshire, Cardiff Central, Cardiff North, Cardiff West, Ceredigion, Dwyfor Meirionnydd, Islwyn, Llanelli, Montgomeryshire, Rhondda, Torfaen).
Meanwhile, 18 of the existing constituency names would remain the same.
The Commission said six constituencies would have an area over 1,000 kilometres squared (Aberconwy, Brecon and Radnor, Caerfyrddin, Ceredigion Preseli, Dwyfor Meirionnydd, and Montgomeryshire and Glyndwr).
Four of these - Caerfyrddin, Ceredigion Preseli, Dwyfor Merionnydd, and Montgomeryshire and Glyndwr - would be between 2,000 and 3,000 kilometres squared, while Brecon and Radnor would be over 3,000 kilometres squared.
Where electoral wards are currently split across more than one existing parliamentary constituency the Commission has proposed they should be allocated entirety to just one constituency.
Secretary to the Boundary Commission for Wales, Shereen Williams, said: "We're confident that our proposals are a strong first attempt to create a workable map of 32 Welsh constituencies.
"The purpose of our initial proposals however is to start the conversation about how the new map will look.
"Nobody will know your local area as well as you do, so get involved in the consultation and let us know your views.
"As we proceed with the review, we're highly likely to make some changes to our proposals, so your responses to the consultation could make a significant difference."
The new proposals and consultation portal will be available on the Boundary Commission for Wales website, www.bcw-reviews.org.uk, from midnight on September 8.
The consultation period will close on November 3.
Plaid Cymru's Westminster leader described the UK Government's plan to reduce the number of Welsh MPs from 40 to 32 as "the most recent of steps on the Tory pathway to taking back control to Westminster".
MP Liz Saville Roberts added: "Year after year the Tories have introduced changes to electoral arrangements that seek to tighten their grip on power."