Nicola Sturgeon has said she will not rule out a legal challenge over Westminster's refusal to allow Scotland to stage a second independence referendum.
The First Minister today said when she will "cross that bridge" when she reaches it, as she stepped up the pressure on Boris Johnson to grant a Section 30 order which would allow Holyrood to hold a vote on leaving the UK.
And Constitution Secretary told SNP delegates at the party's Autumn conference that such a challenge "cannot be ruled out."
And the SNP leader, in Aberdeen for the party's Autumn conference, insisted that Scots would vote for independence by a "significant margin" if another referendum is staged. Ms Sturgeon revealed that she is to seek a Section 30 order from Westminster in the coming weeks, but this has so far been rejected by the UK Government, which has control over the constitution.
The Scottish Government insists this position is "unsustainable" but has rejected holding an unauthorised "wildcat" referendum. But Ms Sturgeon would not rule out a legal challenge when quizzed about this today.
"I'm going to take things step by step" Ms Sturgeon said when quizzed about a possible legal challenge on BBC Radio Scotland's Good Morning Scotland today.
"If and when we reach that bridge I will come and talk to you and set out how I intend to cross it."
Asked again if a legal challenge was "an option", Ms Sturgeon added: "I'm not going to get drawn into options or speculate about what might happen in the future."
She insisted that her "Plan A", for a legally binding referendum, following the precedent of the Edinburgh Agreement signed by David Cameron and Alex Salmond, which paved the way for the 2014 vote, is the way to proceed.
""It's the one that is best capable of delivering independence."
The First Minister insisted that the divisions which followed the Brexit referendum, following a narrow 51%-49% result were not "inevitable." Polling evidence suggests Scots are split down the middle on the issue of independence, but Ms Sturgeon believes that she can win a resounding victory if Scots are asked again about leaving the UK.
"I believe this will be the case, I can't sit here and prove it to you now, but when Scotland comes to take this decision again, Scotland will vote by a significant margin to be an independent country."
The UK Supreme Court recently stepped in to block the UK's Government's attempt to prorogue Parliament and Mr Russell hinted that a changing mood among the courts may
He said: "I do think we're seeing an interesting period.
"For a long time it appeared constitutional jurisprudence wasn't something that we tended to rely on."
"Now we're beginning to see the development of certain things taking place, so I don't know.
"It cannot be ruled out."
The Nationalist movement in Quebec has previously tried to seek independence through international law, but the case was rejected by Canadian courts.
But Mr Russell hinted there may be a difference in going to court to seek a referendum, rather than independence itself.
"There is a difference between the right to self-determination and the right to secession."
He added: "I think we've moved into a different time, there are different currents flowing here. I don't know."