Plaid Cymru politicians held talks six months ago about trying to remove Adam Price as leader, leaked texts seen by BBC Wales said.
Messages from the party’s Luke Fletcher said colleagues were discussing whether Mr Price was fit to lead the party over a failure to deal with allegations of bullying and sexual impropriety.
It comes after a review found a culture of “harassment, bullying and misogyny”.
The Senedd group said it shared the party’s distress about the findings.
But it did not respond to questions about whether Mr Price still had the wider party’s support.
Mr Price has refused to stand aside following Nerys Evans’s report, and said he would be “abdicating” his responsibility if he quit.
He apologised to all those who experienced or witnessed unacceptable behaviour and said the party was a product of the society it was trying to change.
The WhatsApp exchanges between a former party staff member and the Member of the Senedd for South Wales West detail discussions last November over a plan to replace Mr Price.
The texts suggested Mr Price lost the confidence of several party figures, who were keen to install the Ynys Môn MS, Rhun ap Iorwerth, as leader.
In one of the messages, Mr Fletcher said he had “spoken to Rhun” and “told him that I’d back him”.
He went on to say that a meeting had taken place among a number of Plaid Cymru MSs concerning the leadership on 15 November.
That was about a week after the South Wales Central MS, Rhys ab Owen, was suspended from the party’s Senedd group.
He is under investigation by the Senedd’s standards watchdog, over an alleged breach of the code of conduct.
Mr Fletcher said that during the meeting there was “a reluctance to push the button… but I think people can be persuaded”, before adding that “things are still yet to come out”.
In response to later messages, he added he was “sick of everyone pretending everything is OK” and that Plaid Cymru was “the definition of hypocrisy”.
Mr ap Iorwerth admitted “major changes” were needed in messages to the staffer sent around that time.
He went on to say: “It is clear to me that we are at a critical juncture for the party.”
In later exchanges, Mr Fletcher also references the North Wales MS, Llyr Gruffydd, saying he “doesn’t think there’s a way back for Adam”.
Following publication of the Plaid Cymru report, a former Welsh Labour cabinet minister called for Plaid Cymru’s co-operation deal with the Welsh government to end.
Ken Skates MS, a former economy minister, said he did not want to deal “with bullies, misogynists or anyone who discriminates against others”.
Plaid Cymru is in a co-operation deal with the Welsh government, which sees Labour ministers work with the party on a range of policies including childcare and free school meals.
Asked on the BBC Politics Wales programme if she agreed with Mr Skates, Climate Change Minister Julie James MS said: “I think it’s a matter for Plaid Cymru.
“They will want to look very carefully at that report and it’s a matter for them to put their own house in order.
“The difficulty with the Welsh system, of course, is that we have to work with someone and, actually, co-operation agreements across the parties in Wales are things that have brought stability to Wales and support from a large number of people.
“So, it’s about more than that, isn’t it?
“But the party clearly needs to look at that report very carefully,” Ms James added.
In a statement, the party’s Senedd Group said: “Plaid Cymru Group members have actively established confidential avenues through which staff could raise any concerns they may have about the culture within the party.
“The Plaid Cymru Senedd group share the wider party’s distress upon reading the findings of Nerys Evans’s report and echo the calls for the recommendations to be implemented at pace”.
On ITV’s Sharp End previously, Plaid Cymru Senedd group chairman Mr Gruffydd denied claims made in a Wales Online article of a “toxic atmosphere” in his party where people are afraid to report allegations.
He said he did not recognise that there was a wider problem within Plaid Cymru.
Mr Fletcher, Mr ap Iorwerth and Mr Gruffydd were also approached for comment.
Source: British Broadcasting Corporation