Boris Johnson has swiftly rejected Nicola Sturgeon’s demand for a second Scottish independence referendum as the two leaders faced the start of a constitutional war of attrition following the General Election result that saw the Conservatives and the SNP both enjoy landslide victories.

In a telephone call from Downing St last night, the Prime Minister reiterated his “unwavering commitment to strengthening the Union”.

HeraldScotland: Camley's Cartoon: SNP's indyref2 demand.Camley's Cartoon: SNP's indyref2 demand.

“On Brexit, the Prime Minister said that he was now in a position to get this done in a way that allowed the whole of the UK to move forward together, providing certainty for Scottish businesses and improving the lives of people right across Scotland,” explained a No 10 spokesman.

He added: “The Prime Minister made clear how he remained opposed to a second independence referendum, standing with the majority of people in Scotland who do not want to return to division and uncertainty. He added how the result of the 2014 referendum was decisive and should be respected.”

READ MORE: Defeated Tories can't stand in way of Indyref2, says Nicola Sturgeon

Hours earlier in a post-poll speech in Edinburgh, the First Minister addressed Mr Johnson directly on the issue of indyref2, saying: "Let me be clear, this is not simply a demand that I or the SNP are making.

"It is the right of the people of Scotland and you as the leader of a defeated party in Scotland have no right to stand in the way," she declared.

Ms Sturgeon acknowledged that not all those who had voted SNP supported independence but she said she hoped there was “a point of unity” on it being for Scotland to decide its future, not Westminster.

The FM, who is expected to visit the House of Commons early next week to address her strengthened contingent of SNP MPs, confirmed she would formally request the powers for Holyrood to hold a ballot, saying the Scottish Government would "publish the detailed democratic case for a transfer of power to enable a referendum to be put beyond legal challenge".

Earlier, her colleague Ian Blackford, who leads the Nationalists at Westminster, claimed the election result had left the UK in a "constitutional crisis" and insisted the "right thing" for the PM to do would be to permit a second vote on Scotland’s future.

Noting that that if people in the rest of the UK wanted to leave the EU "that should be their choice," the Highland MP added: "There's a voice the people of Scotland have given in supporting the SNP that we want to stay in Europe, that we wish to retain our European membership, and the way we can do that is through a referendum on Scottish independence.”

But David Duguid, the Conservative MP for Banff and Buchan, one of six out of 13 Scottish Tories to keep their seats, told The Herald: “I don't see why the PM should succumb to such pressure[on indyref2].

“With respect to Scotland's desire for independence, nothing has changed. The SNP gained some seats last night but still have only 45 per cent of the vote. That wasn't enough in 2014 and it's not enough now,” he declared.

“Not only that but a number of SNP candidates specifically said in their campaigns that a vote for them would not be taken as a vote for independence,” insisted the backbencher.

With all 650 UK results declared, the Conservatives secured a majority of 80, winning 365 seats; a net gain of 67 compared to the state of the parties at the dissolution of Parliament in November.

Labour was on 203, a net loss of 42, the SNP on 48, a gain of 13, and the Liberal Democrats on 11, a loss of 10.

In Scotland, the SNP won 80 per cent of Scottish seats, including all those in Glasgow.

Ms Sturgeon described it as a “stunning” result, particularly as she said the Tories had bombarded voters on the issue of maintaining the Union.

“They said a vote for them was a vote to deny people in Scotland the right to decide our own future. They said it was a vote to reject an independence referendum. Well, yesterday, the people of Scotland rejected the Tories instead,” she insisted.

Jackson Carlaw for the Scottish Tories admitted their drop from 13 MPs to six was disappointing. “But,” he added, “the numbers show that having made our breakthrough in 2016 and 2017, we have no cemented our position as Scotland’s main opposition party to the SNP. Winning nearly 700,000 votes across the country is a fantastic achievement.”

Scottish Labour suffered another humiliation, losing all but one of its seven seats with Ian Murray, the MP for Edinburgh South - as in the Nationalist landslide of 2015 - being its sole survivor.

Richard Leonard, the Scottish Labour leader, made clear that his party had to listen and rebuild after a “devastating” result, noting: “Constitutional issues have played a major role in our defeat. It is clear that we must do more to win back the trust of people on both sides of the Brexit and Scottish independence debates.”

The Liberal Democrats’ poor performance was underscored by losing their leader Jo Swinson, who like four years ago lost out in East Dunbartonshire to her SNP rival. However, her party retook North East Fife from the Nationalists, meaning they retained their number of four MPs.

In a farewell speech as she stood down as leader, the 39-year-old said her party had to “reflect, regroup and refresh” to combat what she described as a “Nationalist surge” on both sides of the border.

In the wake of the UK election result the stock exchange and currency markets responded positively.

The FTSE 100, which is normally the most watched index in London, took second place to its neighbour, the FTSE 250, which has more UK-focused businesses.

It raced ahead to a record high at one point and closed the day up 714.76 points or 3.4 per cent to 21507.79 while its blue-chip neighbour, the FTSE 100, rose 1.1 per cent or 79.97 points to 7353.44.

The pound jumped by 1.7 per cent to 1.334 against the dollar while it rose by 1.6 per cent to 1.1986 against the euro.

At 7am on Friday, Mr Johnson addressed Tory activists at a victory rally in the party headquarters, thanking them for helping him secure the largest Conservative majority since Margaret Thatcher in 1987.

"And with this mandate and this majority we will at last be able to do what?” he asked, to which the activists shouted: “Get Brexit done.”

Later, after a visit to Buckingham Palace to formally accept the Queen’s invitation to form a new government, the PM addressed the nation from a lectern outside the famous black door of No 10, insisting his One Nation Conservative administration was the “people’s Government”.

He thanked voters in Labour heartlands for switching to the Tories and placing their trust in them, stressing how going forward there would be a strong emphasis on boosting the NHS.

“We will work round the clock to repay your trust and to deliver on your priorities with a Parliament that works for you," declared Mr Johnson.

He addressed those who did not vote for the Conservatives and wanted to remain in the EU, saying his One Nation Government would “never ignore your good and positive feelings of warmth and sympathy towards the other nations of Europe".

READ MORE: How every constituency voted in Scotland

And, after more than three years of bitter arguments over Brexit, he appealed for unity, adding: "I urge everyone to find closure and to let the healing begin."

The PM is now expected to reintroduce his Brexit deal in the Commons next week following the Queen's Speech and State Opening of Parliament on Thursday.

Meanwhile, the acrimonious fall-out to Labour’s defeat began as Mr Corbyn announced he would step down, not immediately but early next year, once the party’s ruling National Executive met to decide the way forward.

He lay the cause of his party’s defeat on Brexit, saying: “This election was taken over ultimately by Brexit and we as a party represent people who voted both Remain and Leave.

"My whole strategy was to reach out beyond the Brexit divide to try and bring people together, because ultimately the country has to come together."

But many of his critics laid much of the blame on his leadership.

Phil Wilson, who lost Tony Blair's former seat of Sedgefield to the Tories, said attempts by the leadership to put the result down to Brexit was "mendacious nonsense".

"Jeremy Corbyn's leadership was a bigger problem. To say otherwise is delusional. The party's leadership went down like a lead balloon on the doorstep," he claimed.

Mr Murray, a long-standing critic of Mr Corbyn, warned his colleagues: “This party must listen, this party must respond or this party will die.”