In a pre-released excerpt from her speech, the First Minister was due to say that the UK's decision to leave the EU amounted to "an attack on the very foundations of the devolved parliament”.
However, amid criticism from opposition parties over her comments, she then failed to deliver the line itself.
Scottish Conservative constitution spokesman Adam Tomkins has written to the First Minister this morning urging her to say whether she stands by the claim, or has retracted her stance.
In his letter, he said:
"Yesterday, your official Scottish Government spokesman briefed excerpts of your speech to the media prior to your speech at the David Hume Institute.
"In a passage about the impact of Brexit, it included this, rather bizarre, sentence: 'So what we have is in effect an attack on the very foundations of the devolved parliament we voted for 20 years ago.'
"Given the fact that the UK Government has made it clear that ‘no decisions currently taken by the devolved administrations will be removed from them’ and that it intends to ‘use the opportunity or bringing decision making back to the UK to ensure that more decisions are devolved’, this claim appears to be utterly without foundation.
"This is something you appeared to recognise yourself, given that you did not then actually repeat the words, despite it having been reported widely in the media.
"Given the confusion created by your briefing note, I would therefore be grateful if you could clarify your position.
"Do you believe that our departure from the European Union is ‘an attack on the very foundations of devolved parliament’, or do you now accept, in hindsight, that this suggestion was simply scaremongering on your part?”