Nicola Sturgeon has called on a former Scottish government minister to stand down as an MSP after he admitted inappropriate behaviour towards women.
Mark McDonald has resigned from the SNP, but intends to remain as an independent MSP at Holyrood.
Ms Sturgeon told BBC Scotland that it would be "appropriate to give his constituents the opportunity to elect a new MSP".
Opposition parties have also urged Mr McDonald to stand down from Holyrood.
Ms Sturgeon said: "My view is clear. He was elected as an SNP MSP. If his behaviour is such that he himself considers he cannot continue as an SNP MSP, then it would be appropriate to give his constituents the opportunity to elect a new MSP".
The first minister said the party could not force Mr McDonald to stand down as an MSP, and it was therefore "a matter for him".
Asked if Mr McDonald had jumped from the SNP before he was pushed, she added: "He made his own decision. I wasn't aware until shortly before he made the statement today that that was his intention.
"He clearly has made that decision on the basis of the findings that were shared with him yesterday and the essence of which were published today, so people can draw their own conclusions from that."
The SNP leader also insisted the party had upheld its "duty of care" for Mr McDonald, and had taken steps to ensure there were "support arrangements in place" for him.
And she said the party would be "very optimistic" about winning a by-election in Aberdeen Donside if Mr McDonald did stand down from Holyrood.
Mr McDonald won a huge 11,630 majority in the last Holyrood election in 2016 after securing 56% of the votes.
What are the allegations against Mr McDonald?
Mr McDonald resigned as childcare minister in November after admitting causing a woman "considerable distress" through inappropriate text messages.
But he pledged to stay on as an MSP in order to "continue to serve my constituents to the best of my ability."
His decision was initially backed by Ms Sturgeon, but the SNP announced on 16 November that he had been stripped of the party whip and suspended as a member while fresh allegations were investigated.
The SNP has confirmed that the investigation examined Mr McDonald's behaviour towards three women.
It concluded that his "inappropriate behaviour" had been "deliberate in nature".
The SNP said Mr McDonald's actions had included:
- Inappropriate and unwanted text and social media messages
- Unwanted attention causing distress
- Persistent behaviour over an extended period of time
- Exploiting his position of power
The investigators who examined the allegations said the MSP should have known that his actions were inappropriate for someone in his position.
They also said they were not able to reach a "definitive conclusion" on a further allegation of inappropriate physical contact during a social event.
What does Mr McDonald say?
Speaking at a media conference in Aberdeen on Tuesday afternoon, Mr McDonald admitted: "My behaviour towards two individuals fell below the level of professionalism that they were entitled to expect of me, whether in a professional or a social context."
He has not been seen at parliament since resigning as a government minister, but insisted he had "continued to act diligently as a constituency MSP" during his absence.
He insisted his conduct had not been in any way physically abusive, and said it was "certainly not my intention to cause any upset, discomfort or offence to those concerned".
But he admitted it was "clear through the concerns highlighted in the report that I have done so".
Mr McDonald added: "That is something which I deeply regret. I would like to take the opportunity here and now to offer a public and unreserved apology to those individuals for the hurt and offence that I have caused them."
He said he had only been informed of the allegations against him on 14 January, and had been allowed to read the findings of the investigation on Monday afternoon.
He also said he had been working with a "behaviour coach" in order to "see myself as others see me" and to "begin to truly understand the potential effects on others of my past actions".
He added: "As a result, I hope that I am well on my way to becoming a better, more empathetic and considerate person for having undertaken these sessions, although that will clearly be for others to determine."
His announcement that he had resigned from the party came ahead of an SNP group meeting at Holyrood, where his colleagues had been due to vote on whether or not to allow him back into the party.
What has the reaction been?
Opposition parties have questioned Mr McDonald's decision to quit the SNP but stay on as an MSP.
The Conservatives called on the SNP to "come clean and publish the report into his behaviour so that the public can judge whether he is fit to remain as an MSP."
And Labour MSP Rhoda Grant said: "The message from this statement today is that Mark McDonald considers the reputation of the SNP more important than the standards expected of an MSP."