Dafydd Elis-Thomas was Plaid president from 1984-91 Plaid problems overshadow future

As Plaid began its annual conference in Aberystwyth, the assembly presiding officer said it had to "grow and adapt" to become a party of government.

Asked if he would go for the leadership next May, Lord Elis-Thomas said it was too early to speculate.

He spoke as another former president, Dafydd Wigley, said Plaid faced an "horrendous" future without change.

I'm a good member of the Church in Wales. There's only one saviour - certainly not me Dafydd Elis-Thomas

Plaid's leadership has been the subject of much speculation after it emerged that some members want Lord Elis-Thomas to return to the presidency he held for seven years until 1991.

Party chairman John Dixon has criticised "small groups of members" who are "plotting to overturn the democratic choice of the party".

Lord Elis-Thomas told BBC Radio Wales said he would not use such a word as conspiracy because, he said, "clearly nominations do open, there will be elections," adding: "It's a democratic decision for members of the party."

(L-R): Plaid president Dafydd Iwan and a predecessor, Dafydd Wigley

Gwynedd councillor Dafydd Iwan holds the presidency, and Ieuan Wyn Jones leads the 12-strong assembly group.

But Lord Elis-Thomas, the assembly member for Meirionnydd Nant Conwy told Good Morning Wales that if an AM was elected president, he or she would also automatically also become assembly group leader.

He said he did not believe it was a "neat scenario" that he would stand down as presiding officer next year to go for the leadership.

"I have an all-party position," he said. "I can only do my job if I have the confidence of all AMs, including the biggest party, which is currently Welsh Labour.

The consequences - for the party and for Wales - could be too horrendous to contemplate Dafydd Wigley tells his party why it must change

"Therefore I'm not going to do or say anything which undermines the assembly or my role as presiding officer."

Speculation has increased since Plaid's lost Ceredigion at May's general election, and failed to regain its main target seat of Anglesey, but Lord Elis-Thomas denied the results had been "particularly poor".

"I don't think these minor swapping of seats in west Wales are of eternal significance in Welsh politics," he said. "The great thing that is happening in Welsh politics is the continuing irreversible decline of Welsh Labour."

Asked if he was the saviour of his party, Lord Elis-Thomas said: "I'm not a saviour of anything.

"I'm a good member of the Church in Wales. There's only one saviour - certainly not me."

Meanwhile, Mr Wigley, who will be confirmed as Plaid honorary president at the conference, has told party magazine Triban Coch must change or "the consequences - for the party and for Wales - could be too horrendous to contemplate".

He said the current leadership system had confused the public and media, while the party had to decide if it was "basically oppositionalist," or was a party of government, and prepared to enter into coalition.