The heightened chance of breaking-up the United Kingdom was one unintended consequence of prime Minister Boris Johnson's huge snap national election victory Thursday, with Scottish nationalists promising to launch their bid for a second referendum on Scottish independence as early as this week.

Scottish first minister Nicola Sturgeon claims her Scottish National Party (SNP) winning 48 of Scotland's 59 seats in the UK House of Commons is a clear mandate for a new independence referendum. The SNP's unexpectedly huge win has prompted Sturgeon to step-up her demands for another independence bid.

Johnson has long been an opponent of Scottish independence and campaigned against it during the Sept. 18, 2014 referendum. The referendum question at the time was, Should Scotland be an independent country?The "No" vote won with 2,001,926 (55.3%) votes while 1,617,989 (44.7%) voted "Yes."

Johnson's told Sturgeon by phone Friday he still opposes another Scottish independence bid.

"I was firm with him that I have the mandate to offer people a choice," she said. "He reiterated his opposition to that. But you know, let's focus on reality here -- the election this week was a watershed moment for Scotland.

She said Scottish voters had "rejected the Tories, said no to Brexit and made clear we want our future in our own hands."

Sturgeon has long contended Scotland deserves another vote on becoming an independent country because it's being taken out of the EU against its will.

Sturgeon said Scotland had delivered a "strong, unequivocal vote" to remain in the EU. The Scots voted overwhelmingly to stay in the European Union, 62% to 38%, during the Brexit vote of June 23, 2016, called by former prime minister James Cameron. On the other hand, the entire UK voted  51.9% leave the EU.

Sturgeon said Scotland's "Stay" vote delivered a "strong, unequivocal vote" to remain in the EU. At the time, she also noted a second independence referendum was "highly likely" after Brexit.

An SNP manifesto said the Scottish Parliament should have the right to hold another referendum if there was a "significant and material change" in the circumstances that prevailed in 2014, such as Scotland being taken out of the EU against its will.

"It is, therefore, a statement of the obvious that a second referendum must be on the table, and it is on the table," according to Sturgeon.

"Scotland very clearly wants a different future to the one that's been chosen by much of the rest of the UK, and Scotland wants to have the right to choose its future," she said Saturday.