Speaking as the Scottish government published a draft bill on a second independence referendum on Thursday, the first minister suggested that if Scotland does not remain in the European single market as the UK leaves the European Union, then she could re-run the 2014 vote.

"If we find that our interests cannot be properly or fully protected within a UK context then independence must be one of the options open to us and the Scottish people must have the right to consider it," Sturgeon said.

The Scottish National Party (SNP) leader's warning comes after her opposite number in Westminster, UK Prime Minister Theresa May, said earlier this month that all of the UK would leave the European Union.

The first minister's comments open the possibility of a referendum before the UK formally leave the EU, a process that is due to be completed in March 2019.

Thursday's draft legislation proposes a very similar ballot to that which 55 percent of Scots voted against two years ago. Citizens living in other EU member states would have a vote - unlike in June's EU referendum - and once more the franchise would be extended to 16- and 17-year-olds.

But the draft bill does not mean a second referendum will definitely be held. There could be legal obstacles.

Legal obstacles

Westminster would have to give the devolved Scottish parliament permission to hold such a vote. Already May has said there is a mandate for a second referendum.

Even if London acquiesces, the Scottish National Party (SNP) is unlikely to call a vote until polls change. Currently a majority of Scots remain in favor of staying the UK, despite 62 percent voting to remain in the EU.

Sturgeon has said that a second referendum is "highly likely," but that this could be avoided if a deal were reached that allowed Scotland to retain access to the European Single Market.

But Michael Keating, professor of politics at Aberdeen University, says that it is not feasible that Scotland could remain in the EU when the rest of the UK withdraws.

Either in or not

"You're either in it or you're not in it, so just imagine, could Scotland stay in the single market if the rest of the UK were to leave the single market? That would imply an economic boundary between Scotland and England - customs posts, all the rest of it, checks on product standards, rules of origin - that is the one thing that nobody wants," he told DW.

Some nationalists see Brexit as an opportunity to repatriate powers to the Edinburgh parliament that are currently controlled in Brussels. Former SNP cabinet minister, Alex Neil, has said that leaving the UK gives the Scottish Government a "golden opportunity" to assert control over farming, fishing, employment law and other powers before pushing for independence in the 2020s.

But Sturgeon has maintained that membership of the European Union is vital to Scotland's economic interests.

Meanwhile polls suggest Scots are divided on whether to have another referendum at all.

"No way. We have had one already we don't need another," says the barman in the Union Bar in Glasgow.

The Union Bar reflects one of the most pro-UK faces of Scotland, those who feel allegiance to Protestants in Northern Ireland. The union flag flies outside; inside colorful portraits of King William of Orange, the hero of Protestant lore, astride his horse look down from the walls.

'White and British'

"We're white and British and we're staying that way," barman Stewart, who asked not to give his full name, told DW. "In Northern Ireland so many died to stay British. If we left we'd be stabbing them in the back."

Not everyone, however, is so solidly pro-union. Pensioner Liz Gray voted 'yes' in 2014. "I like Nicola Sturgeon. She knows her job," Gray says.

The biggest question in Scottish politics right now is whether - and when - Scots will have another chance to vote on leaving the UK.

John Curtice, professor of politics at Strathclyde University, says the possibility of a second referendum is 50-50. "Sturgeon's threat is not an empty threat but her position is not as strong as she would like it to be," he told DW.

In September, the nationalists unveiled a new "conversation" to build support for leaving the UK including a plan for the party's 125,000 members to approach two million Scots to assuage their fears about leaving the UK. A "growth commission" will be established to answer the economic questions - most notably on currency - that dogged the 'yes' campaign in 2014.

In a UK wracked by uncertainty over Brexit, the SNP has positioned itself as the party with a plan. "We want to build, if we can, a consensus on the way forward," Sturgeon said of independence recently.

But such public confidence betrays private concerns about the prospects of winning a second referendum, at least in the short-term.

Economic woes

Economically, Scotland is in a far weaker position than in 2014. Oil revenues have collapsed amid a global price war: tax receipts from the North Sea have fallen from over £11 billion (12.3 billion euros) in 2011-12 to just £60 million last year. Scotland's deficit - the difference between what the government raises in tax and what it spends - has spiraled to 9.5 percent of GDP. The overall figure for the UK is 4 percent.

Privately many senior SNP figures are wary of another bite of the independence cherry so soon. They are right to be circumspect, says Andrew Tickell, a SNP supporter and columnist for the Times.

"The SNP have to have credible answers to the questions about currency and finances. But the SNP are terrible at that. It's hard to have confidence that that work has been done," Tickell told DW.

Some nationalists, however, argue that with Brexit and an increasingly right-wing Conservative government in London, the time has never been better to push for independence.

"I think now Nicola Sturgeon has to call it," says Suzanne McLaughlin, a former SNP candidate and owner of the pro-independence Yes Bar in Glasgow's city center. "Now is the time."