Dafydd Iwan and Cynog Dafis are contesting the Plaid presidency

Dr Laura McAllister, a political analyst at Liverpool University, has claimed that differences between Plaid's "cultural nationalist" and "socialist" wings are holding the party back.

But Dafydd Iwan, who is hoping to become Plaid president later this year, said it was "a strange piece of advice" from Dr McAllister, who is originally from Bridgend.

Cynog Dafis, who is Mr Iwan's rival for the presidency, believes a split would be a political disaster, and questioned whether serious disagreements really existed within the party.

The opening round of the contest to name the successor to Ieuan Wyn Jones as President of Plaid Cymru will take place on Monday.

Our main mission is to secure full self-government for Wales and, once we get that clear, these divisions will disappear Dafydd Iwan

Mr Wyn Jones announced he would be stepping down from the role after Plaid's disappointing showing in May's Welsh assembly elections.

Mr Iwan, currently Plaid vice-president, admitted he "did not know of any political party which has gone into voluntary disintegration".

"I think there is a potential for division in all political parties, and those divisions come to the fore when there is a lack of clarity on the main mission," he said.

"I think Plaid Cymru has diluted its main mission in the past few years.

"Our main mission is to secure full self-government for Wales and, once we get that clear, these divisions will disappear."

Emerging parties

Mr Iwan believes the political structure in Wales should have been rearranged with devolution in 1997.

"Ideally after devolution, there should have been some realignment and the people in the Labour party who do take Welsh politics seriously, could have happily worked with most people in Plaid Cymru."

But he argues this realignment would occur naturally if an independent parliament is delivered.

"After we have achieved self-government, there will be a natural tendency for people to define themselves in different political parties."

Since devolution, the Wales Independence Party has emerged, as has Welsh language pressure group Cymuned.