What to Know About Scotland's New Push for Independence

It's been a busy few years for the U.K., as the country went to the polls three times—for the Scottish independence referendum in September 2014, the general election in 2015, and the vote on Britain's membership of the EU in June 2016.

Now, as if that wasn't enough, it looks like the first of those, the Scottish referendum, could be facing a re-run as a direct result of Brexit. "On the one hand, I'm kind of fueled for the fight," Blair McDougall, a former Labour Party adviser who ran the cross party pro-U.K. campaign "Better Together" in 2014, tells Newsweek. "On the other hand, I just think it's a colossal waste of time."

Waste of time or not, with Scottish National Party (SNP) leader and First Minister Nicola Sturgeon calling for it, a rerun could be incoming. But is Scotland actually set to leave the U.K.—and how could things pan out now? Here's what you need to know.

When could Scotland hold a second referendum?

Sturgeon wants to hold a vote between fall 2018 and spring 2019, which she says would give enough time for Brexit negotiations (set to start Wednesday and likely to last for two years) to make substantial progress, but would also leave time for Scotland to leave the U.K. and still remain in the EU—her ideal scenario.

British Prime Minister Theresa May disagrees. She says the Brexit negotiations are disruptive enough, and to vote on Scotland's future during them would leave Scots unsure on what exactly they were voting for. Her favorite soundbite, which Brits have already got used to hearing, is: "Now is not the time."

May would probably struggle to deny Scotland the referendum indefinitely, but she may succeed in holding it back until after Brexit, which is scheduled for 2019.

If Sturgeon decided to defy May and call a referendum without Westminster's permission, it is unclear if such a move would be constitutionally valid, says Alan Renwick of the UCL's constitution unit. While the power to decide the future of the union lies in Westminster, that does not mean Sturgeon couldn't hold an advisory referendum on the issue—one that expressed the will of the Scottish people, but did not legally require action from the government. While that might sound a bit limp, the Brexit referendum was also technically only advisory. The vote to leave the EU didn't formally require lawmakers to do anything, but its political weight was such that nobody really questioned the U.K. would leave after the result.

However, Sturgeon wants people to see any independence referendum as legitimate. That's especially true because if an independent Scotland were to seek membership of the EU, Spain's approval would be crucial. Spain opposes its own secessionist movement in Catalonia, and the important difference with Scotland would be the government sanctioning a referendum; Catalonia does not have government approval for its departure process. For Sturgeon, getting Westminster's approval may be central to bringing Spain onside.

Who would win?

The headline poll figures don't suggest much of a shift since 2014. Back then a Yes vote for independence took 45 percent of the vote, while No took 55 percent. Since the EU referendum, most polls have shown numbers in the higher 40s for Yes, and around 50 for No, with the rest of the respondents saying they weren't sure what they would vote. But in the last independence vote, the polls shifted significantly during the long campaign—support for independence was at around 30 percent when the referendum was called—so the numbers are not definitive.

The impact of Brexit, which hardly anyone was even talking about at the time of the last referendum, could be important—but it's unpredictable which way it would influence voters.

On the one hand, Pro-EU Scots who voted No last time might be persuaded that England is becoming isolated from the world, and if they want to stay open and connected to Europe and the world they should vote Yes to leaving the United Kingdom.

On the other hand, some of those who voted Yes in 2014 also voted for Brexit in 2016: There is a strand of hardline nationalists who want to see Scotland unencumbered by commitment to any union, whether it be the supranational EU, or the U.K.

Sturgeon is already framing the debate as a choice between two change options, rather than between change and the status quo. "The option of no change is no longer available. But we will give the Scottish people a choice about the kind of change we want," she said in a speech in March.

But if Sturgeon pushes an anti-Brexit, pro-EU line too much, the small but significant group of former Yes voters who also pushed for Brexit may not back her. When the margins are this slim, even the votes of a fringe group like this could make all the difference.

McDougall—who is more confident of a vote against independence in this referendum than he was in the last—says this group of nationalist Brexiters could be key: "One set of elites in London is much the same to them as one set in Brussels." McDougall and other pro-union observers also point out that, in 2014, the SNP said an independent Scotland would follow an anti-austerity, high public spending economic policy. But that relied on the new country taking a share of then-lucrative North Sea oil revenues. The slump in global oil prices in the intervening years has hurt that part of the party's case.

What would happen if Scotland left?

After 2016, journalists aren't alone in doubting their ability to predict what's going to happen in a couple of months' time—let alone something as far off and uncertain as Scottish independence. But there are some known unknowns.

We know an independent Scotland would apply to become a member of the EU, but the question would be whether it would need to go through anything like the normal accession process, which takes years. The EU may see the political appeal of "fast-tracking" a new member so soon after its first defection. But uncertainty over the strength of the new country's finances would also play a part in deciding this process.

There would be questions, too, over the future of the approximately 100-mile border with England. Ireland and Northern Ireland have maintained a barely existent "soft border" for years, with only the most minimal of customs checks. But they have also both been within the EU. If Scotland joined the EU, or remained a member of it, it might be hard to sustain that kind of arrangement, which could prove a big hit to businesses that operate on both sides of the border.

And the SNP's white paper on independence—a fairly detailed program for government published before the last referendum—is now wholly outdated, thanks to oil price changes and Brexit. The party would need to produce a compelling new vision for independence, taking into account the new financial and political realities.

Scottish independence is some way off, and Sturgeon's battle will likely be more difficult this time than in 2014. But with the U.K.'s place in the world in flux, it would be foolish to write it off just yet.