Both men considered likely challengers to Leanne Wood for the leadership of Plaid Cymru have set out their visions for the future of the party.

Adam Price says Ms Wood should share the top job and says that if his proposal for a 'co-leadership' is accepted, he won't challenge her on this occasion.

Rhun ap Iorwerth says the party must become a 'people-and-ideas-driven movement' which appeals to those with views in the centre of politics can feel as comfortable as those on the left.

They've set out their views in newspaper articles published this morning.

Leanne Wood has made no comment so far in response to the moves.

In his Western Mail article, Adam Price says that Plaid has 'generally failed to consistently articulate a comprehensive and compelling vision of the future.'

He says the party can't change under a single leader and should instead be led by two people, one male and one female.

The senior AM, and former MP, Adam Price has written a newspaper article setting out why he thinks co-leadership is the way the party can renew itself without a leadership election.

A co-leadership model, where two leaders, male and female, jointly lead the party, can give us a radical and powerful leadership that will avoid the traditional vulnerabilities of placing power in a single pair of hands.

Adam Price AM, Plaid Cymru

In his article, Rhun ap Iorwerth writes that Plaid Cymru must broaden its appeal beyond the traditional left-right view of politics.

That can be seen as an implicit criticism of Leanne Wood's positioning of Plaid as emphatically a party of the left.

He writes that Plaid has a choice:

Either a) we limit the numbers who can get on board with such a Plaid Cymru vision, or b) we try to attract as many people to the cause as possible – people driven not exclusively by the left-right political axis, but who have a genuine interest in the Welsh-British axis and in wanting to see the development and growth of our nation.

Rhun ap Iorwerth AM, Plaid Cymru

The party's constitution allows for a leadership challenge every two years.

Wednesday is the deadline for anyone interested in making such a challenge to come forward.

Both men have been formally nominated as leadership candidates by their constituency parties and a number of other Plaid groupings.

Rhun ap Iorwerth ends his article by stating on the record that he's considering whether or not to stand, but he doesn't use it to make an announcement.

To those who’ve read this far waiting for an announcement... I apologise. This wasn’t the launch of a campaign. But it does prove my intense strength of feeling that we need to be clearer about our vision, and be willing to discuss it. I’m on the record saying I’m considering my response to Leanne’s invitation for a debate on the leadership. What that means in reality is that I’m speaking to as many people as possible about how best to take Plaid Cymru forward. We’re in this for Wales, not ourselves.

Rhun ap Iorwerth AM, Plaid Cymru

I understand that Adam Price has written to Leanne Wood and the other group members saying that if the co-leadership change he's suggested is accepted he will 'politely decline' the nominations he's so far received and won't take part in any leadership contest at this stage.

That could be seen as an implicit ultimatum but I gather his letter doesn't include any such threat.

His article sets out why he believes the party has not made more progress, it also insists it's not about dissatisfaction with Leanne Wood personally.

I contend that this is not about personalities. For instance, what is the value of simply ousting Leanne via a leadership challenge? One definite consequence is that it would leave a toxic residue of bitterness and recrimination.

Adam Price AM, Plaid Cymru
Credit: ITV Cymru Wales

The latest ITV Wales Opinion Poll suggests that Plaid Cymru voters would prefer Leanne Wood to continue as leader.

Leanne Wood retains a clear lead amongst Plaid Cymru voters Credit: ITV News Cymru Wales

The above figures are based on people who say they would back Plaid Cymru with their regional list votes in an Assembly election. A smaller sample of people would would vote Plaid Cymru in a Westminster shows Adam Price doing much better, with 21% support. Leanne Wood is on 31% and Rhun ap Iorwerth on 14%. Whether this apparently more committed group is more representative of party members, who would actually get to make the choice, remains to be seen.

This is a debate that has been intensifying.

Last week, the former MP Elfyn Llwydtold ITV Wales’s Y byd yn ei Le programme that the party is not moving forward and that a discussion is needed over its leadership.

If you look at any other political party, if that party is not seen to be succeeding, either standing still or going backwards the question of leadership gets raised.

Elfyn Llwyd, former Plaid Cymru MP

Three AMs, Llyr Gruffydd, Sian Gwenllian and Elin Jones, sent a letter Sources close to the three say they've done all they can and it's now up to those who might make a challenge.

Leanne Wood herself told the BBC that if she's not First Minister after the 2021 election, she'll stand down. That might not be soon enough for those who are impatient for change within the party.

For now Leanne Wood is saying little, issuing the briefest of statements about the latest developments.

All proposals will be considered and will follow the appropriate procedures. I am sure all of us are determined to ensure that we continue to work in the most open and democratic manner possible.

Spokesperson for Leanne Wood

If there is a leadership election in Plaid, it will mean that all four of the main political parties in the Assembly will be choosing a new leader.