Boris Johnson declared that his party has "smashed the roadblock" and "ended the gridlock" as he hailed the biggest Conservative majority since the 1980s.

The Prime Minister vowed to unite the country, spread opportunity and "get Brexit done" after his snap General Election gamble paid off and he romped home with an estimated majority of 78.

In a victory speech in central London, Mr Johnson said: "We did it - we pulled it off, didn't we? We broke the gridlock, we ended the deadlock, we smashed the roadblock."

He added: "In winning this election, we have won votes and the trust of people who have never voted Conservative before and people have always voted for other parties. Those people want change. We cannot, must not, must not, let them down."

The Tory landslide prompted Jeremy Corbyn to announce that he will not lead Labour into another election after his party suffered humiliation across the country.

Liberal Democrat leader Jo Swinson lost her seat to the SNP and quit as party leader. Sir Ed Davey and Baroness Sal Brinton will become joint acting leaders ahead of a leadership contest next year.

But the success of the Scottish nationalists and of nationalist parties in Northern Ireland could provide Mr Johnson with another challenge on top of Brexit as it suggests that opposition to leaving the EU is hardening there.

But Tory supporters are unlikely to be worrying about that on Friday after witnessing their party take seat after seat in Labour's heartlands, including some they had never held before.

With most of the 650 seats declared, the Tories are predicted to hold a majority of 78.

And Mr Johnson was on course to finish with more than 43% of the popular vote, the highest for a Tory leader since Margaret Thatcher's victory in 1979 and around the same as Tony Blair's in 1997.

The PM is expected to see the Queen at Buckingham Palace later on Friday and be invited to form a Government.

US President Donald Trump tweeted his congratulations, adding that the UK and US will "now be free to strike a massive new trade deal after Brexit".

And European Council president Charles Michel congratulated Mr Johnson, adding: "We expect a vote on the Withdrawal Agreement as soon as possible.

"(The) EU is ready for the next phase. We will negotiate a future trade deal which ensures a true level playing field."

Mr Corbyn, who had sought to exploit Mr Trump's support for the PM during the election campaign, admitted it had been a "very disappointing" night.

He announced that he would call it a day as leader as he was re-elected in his London seat.

Mr Corbyn said he would discuss with the party how to ensure there was a "process of reflection", adding: "I will lead the party during this period to ensure this discussion takes place."