Jeremy Corbyn is to stand down as Labour leader following a "period of reflection".
The party won its lowest number of seats since 1935 as support crumbled in its former heartlands, with the Conservatives winning a majority of 80.
Mr Corbyn blamed Brexit for Labour's poor showing as he accepted victory in his Islington North constituency, while also criticising media "attacks" towards himself, his family and the party.
"I want to also make it clear that I will not lead the party in any future general election campaign," he announced in a speech early on Friday morning at his constituency count in Islington, north London.
"I will discuss with our party to ensure there is a process now of reflection on this result and on the policies that the party will take going forward.
"And I will lead the party during that period to ensure that discussion takes place and we move on into the future."
Later, Mr Corbyn said he was "very sad" at the party's performance but emphatically denies his policies were the cause of Labour's downfall.
"I don't think they are un-electable at all," he insisted.
"Of course I take responsibility for putting the manifesto forward but I have to say the manifesto was universally supported throughout our party and throughout our movement."
Mr Corbyn added "I've done everything I could to lead this party" but claimed "I don't think the result would have been any different" under a more centrist leader.
He said the "responsible thing to do is not to walk away" and he would stay in post "until there has been someone elected to succeed me" which should be in the "early part of next year".
Asked what he would do next, Mr Corbyn said he would remain an MP and "continue to do the campaigning work I've done all my life".
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The anti-war campaigner, who has represented Islington North since 1983, ran as an outside candidate for the party leadership in 2015 and managed to outlast two Tory prime ministers.
But facing his second general election defeat, Mr Corbyn announced that he would call it a day as leader as he was re-elected in his London seat.
In the 2017 election, Mr Corbyn saw his party win 262 seats. That figure has fallen, with the party winning 203.
The writing appeared on the wall when the Tories managed to win the former mining area of Blyth Valley for the first time ever.
Labour had held the seat since it was formed in 1950, but the Conservatives managed to overturn a majority of almost 8,000 - a 10.2% swing.
Many in the party have insisted Brexit was to blame for Labour's losses - however others pointed the finger firmly at the leadership.
Labour clung on to several North East seats include Newcastle Central, Sunderland Central, Newcastle-upon-Tyne East and Houghton and Sunderland South, but with much reduced majorities.
And in her victory speech, Sunderland Central MP Julie Elliott said it had been a disastrous evening for the party and it must change.
"The party I have been a member of for 35 years has let the country down by not being good enough to win against this awful Tory government.
"People on the doorstep have repeatedly said to me they cannot vote for this party.
"They will come back to us if we become a radical party for change on the centre-left ground which is where we win elections.
"I will play my part... the country needs a Labour government."