Nicola Sturgeon has questioned whether the UK Government is legally entitled to block Scotland staging an independence referendum, insisting: "It's never been tested in court."
The First Minister, who wants to stage a second referendum next year, has insisted it doesn't have to be a repeat of the chaos of the Brexit vote. Power over the constitution in the UK remains reserved to Westminster and it is widely assumed that Scotland could not stage a second referendum on independence without a transfer of power in the form of a "section 30" order as happened in 2014.
But the SNP leader appeared to query this when quizzed on the BBC Radio 5 Live phone-in this morning.
She was asked where Scotland would be left legally if Boris Johnson rejects her demand for a section 30 order if he is returned as Prime Minister after the election.
"Suffice to to say I've thought through all of these things, we'll look at all options if we get into that situation," she said. "I've made it very clear it has to be a legal, legitimate process if we want it to lead to independence.
"But the more, particularly in advance of the election we talk about what happens if we get into that situation, we almost legitimise the right of Boris Johnson to block an independence referendum.
"He doesn't have that right. Morally, it's not for Westminster politicians to decide whether or not Scotland becomes independent, it's for the people of Scotland."
Host Nicky Campbell said that the UK Prime Ministers did have the "legal and constitutional" power to to decide on this.
But Ms Sturgeon added: "That's never been tested. I've accepted the need to have that proper legal process, but actually in point of fact it's never been tested in court exactly what the position would be.
"Politically, I'm a politician is perhaps it's not surprising I say this, but let's get the political solutions if we can and that first step in this is to try to make sure that Boris Johnson is not calling the shots the day after this election."
Ms Sturgeon has said that she would seek a section 30 order from the new Prime Minister before Christmas which would pave the way for a political agreement allowing a second referendum take place.