Scottish First Minister Nicola Sturgeon announced her intention Monday to seek another independence referendum, to be held between the fall of 2018 and the spring of 2019.

However, it is far from clear that a vote will actually happen. Here’s what Canadians need to know.

Didn’t Scotland just vote to stick with the U.K.?

Yes, Scottish voters decided 55 per cent to 45 per cent against independence from the United Kingdom in a Sept. 2014 referendum.

However, two years later Scottish voters were mostly against “Brexit.” They voted 62 per cent voted in favour of remaining in the European Union, while the United Kingdom overall voted 52 per cent in favour of leaving.

That caused at least some of the Scots who voted against independence to re-think whether they will be better off inside a U.K. that has left the E.U., or as an independent nation that could opt to rejoin the E.U.

Why now?

The United Kingdom’s Parliament voted on Monday to allow Prime Minister Theresa May to trigger Article 50 of the country’s treaty with European Union, which means Brexit will move forward.

Sturgeon, who leads the pro-independence Scottish National Party, said Monday she will move quickly to demand another independence vote citing a “hard Brexit.”

May has stated her intention for giving up access not only to the E.U.’s single market, but also the customs union, which some believe is required for the U.K. to gain back full control of immigration. Some call that a “hard Brexit.”

Can the U.K. veto another vote?

Yes. Scotland can only proceed with a new referendum if U.K. Prime Minister Theresa May’s government allows it under a regulation called Section 30.

Colin Barr, senior lecturer at Scotland’s University of Aberdeen, told CTV News Channel that “there’s no guarantee (May) would accept it (and) there’s nothing that says she has to.”

“She doesn’t want to be the prime minister who sees the country break up for the first time since 1707,” Barr added.

But Kurt Hubner, Director of the Institute for European Studies at the University of British Columbia, told CTV News Channel that it would be politically risky for May to refuse a referendum.

What are the polls saying?

Barr says the polls “do not indicate a shift in support in Scotland for independence.”

“There’s been one poll that showed it at 50/50, a straight tie,” he said. “Everything else shows it’s slightly against independence.”

The Ipsos MORI poll found that among Scots who intend to vote, 50 per cent are in favour and 50 per cent opposed.

A YouGov poll conducted late last year found 47 per cent were against independence, 39 per cent were in favour, 11 per cent were unsure and four per cent said they would not vote.

Will Sturgeon press ahead regardless?

Barr said that he believes Sturgeon might back out if polls don’t shift toward independence.

“She left a little bit of wiggle room,” he said.

“If the polls show she’s losing, she may find a way not to call it,” he added.

Hubner said that part of the reason Sturgeon announced her intention to seek a referendum Monday was to signal to May that the U.K. needs to take Scottish interests seriously while negotiating Brexit.