Preseli Pembrokeshire MP Stephen Crabb has criticised plans which could see the return of Dyfed.

Mr Crabb said that the Liberal Democrats’ amendments to the Constitutional Reform Bill, currently going through the House of Commons, would abolish the two existing Pembrokeshire constituencies and merge them with Carmarthenshire and Ceredigion, forming a much larger constituency, named Dyfed.

The reform bill seeks to introduce sweeping changes to parliamentary constituencies and a system of proportional representational voting.

Under the amendment plan, four MPs would be elected by proportional representation to represent a Dyfed constituency.

Mr Crabb, a Conservative MP, said in the event of a hung parliament after the next election, it is thought that the Liberal Democrats will make this system of proportional representation a condition of any pact to form a new government with the Labour Party.

He described the plans as a “dog’s breakfast” which will break the link between an individual MP and a single constituency, leading to enormous confusion for voters over which MP actually represents them.

He also believes that the use of the old Dyfed council name would be meaningless for local people who are strongly attached to a Pembrokeshire identity.

“Local people fought hard to win back Pembrokeshire as a county council after it was previously submerged within the Dyfed local authority area.

“I am amazed that the Liberal Democrats think there will be a strong appetite among people in Pembrokeshire or Ceredigion to see a new Dyfed parliamentary constituency imposed on them. Pembrokeshire is a historic county.

“It has had its own specific representation at Parliament, in one form or another, for nearly 500 years,” said Mr Crabb.

He added: “There is no perfect electoral system, but one that preserves a strong link between constituents and an individual MP is much more preferable to the one being proposed by the Lib Dems or the one currently used in the Welsh Assembly, where regional AMs compete with constituency AMs.

“Local people have already lost their Pembrokeshire health board, which has been merged into the larger Hywel Dda Health Board. There does seem to be an agenda to bring back Dyfed as a political and administrative unit.

“The danger within that is that the specific needs and identity of Pembrokeshire get sidelined.”