Boris Johnson has said he will work "night and day" to repay the trust of voters after he led the Conservatives to an "historic" election victory.
With just two seats left to declare, the Tories have a majority of 76.
Speaking in London, the PM said it was a mandate to take the UK out of the EU next month "no ifs, no buts".
Jeremy Corbyn has said he will not fight another election as Labour leader after the party was swept aside in its traditional heartlands.
In a victory speech, Mr Johnson said it was a "new dawn" for the country - echoing comments Tony Blair made when he won power in 1997.
He thanked Labour voters, many of whom, he said, had backed the Conservatives for the first time.
He said it was his mission to deliver for them by leading a "people's government" and fulfilling the "sacred trust" placed in him.
"The people want change," he said. "We cannot and we must not let them down".