Counting began on Thursday night after a day of elections that will have profound implications for the future of the UK and the Labour Party.
For Labour, Hartlepool was a test of its ability to win back voters in its former Red Wall heartlands.
Labour’s pro-EU candidate Dr Paul Williams gained 8,589 votes and the Tory candidate Jill Mortimer gained 15,529 votes.
After the results were announced, Ms Mortimer said Labour has taken Hartlepool for granted for “too long”, adding that it is “time for change”.
The result comes after a shadow cabinet member admitted Labour was “not close to winning this”.
Shadow transport secretary Jim McMahon, who led the Opposition party’s campaign to hold Hartlepool, said it looked clear that Labour had not “got over the line”.
Mr McMahon told Sky News: “It is pretty clear in the way the ballots are landing that we are not close to winning this despite our best endeavours.
“We haven’t got over the line, that’s quite clear from the ballots.”
Early results in council contests elsewhere also appeared to show voters deserting Labour, as ballots continue to be tallied up across England, Scotland and Wales following the Super Thursday polls – the largest test of political opinion outside a general election.
A Labour source said leader Sir Keir would “take responsibility for these results” as the party looked on the verge of losing the Hartlepool by-election.
The source said: “We’ve said all along the North East and the Midlands would be difficult.
“We also said the places declaring Thursday would be particularly difficult.
“But the message from voters is clear and we have heard it – Labour has not yet changed nearly enough for voters to place their trust in us.
“We understand that. We are listening. And we will now redouble our efforts.
“Labour must now accelerate the programme of change in our party, to win back the trust and faith of working people across Britain.
“People don’t want to hear excuses. Keir has said he will take responsibility for these results – and he will take responsibility for fixing it and changing the Labour Party for the better.”
Hartlepool was held by Labour with a majority of 3,595 in 2019, even as other bricks in the so-called red wall crumbled – in part due to the Brexit Party splitting the Tory vote.
Both Mr Johnson and Sir Keir made three visits during the campaign in a sign of the importance the by-election represents to their parties.
This is a breaking story, more to follow…