Luciana Berger has lost her bid to be Finchley and Golders Green MP, as Tory Mike Freer was re-elected with a comfortable majority of more than 6,500.
Labour came third in the seat as Ms Berger took the Lib Dems to second place, in an election that reshaped the political map of the country and saw Labour suffer its worst result in modern history.
The result meant it was a clean sweep in Barnet for the Conservatives, with Chipping Barnet's Theresa Villiers and Hendon's Matthew Offord re-elected alongside Mr Freer.
Mr Freer saw off Labour with a 1,600 majority in 2017 but now has a 6,562 majority over the Lib Dems, who won 17,600 votes, compared with just 3,463 last time.
In her concession speech at Barnet Town Hall in the early hours of Friday, Ms Berger blamed her defeat on fears of Jeremy Corbyn as prime minister.
She said "country will be poorer" as a result of this election.
Mr Freer praised Ms Berger's “very difficult decision” to stand for the Lib Dems after she quit Labour over antisemitic bullying earlier this year.
"I am sure you will return to Parliament one day and continue your public service,” he said.
Ms Villiers grew her majority, from just 353 to 1,212.
The environment secretary, a staunch Brexiteer in a seat that voted Remain, said it was "clear Brexit has created new fractures"
She said she would "always speak out against antisemitism", adding that Labour "must remove it from their party in order to be fit for office".
Mr Offord defeated Labour's David Pinto-Duschinsky with 26,878 votes compared with 22,648.