Frank Field, who resigned the Labour whip last year, lost his seat in Birkenhead after more than 40 years as an MP.
Mr Field decided to defend his seat as the Birkenhead Social Justice Party candidate after quitting Labour, saying it had become "a force for anti-Semitism".
After losing his seat, he thanked "those voters who over 42 years have given [him] the huge privilege of representing Birkenhead in the House of Commons".
"My debt to them is unlimited," he added.
"We know perfectly well within the parliamentary Labour party there are a number of shadow [members] who, had they been leading the party, some of you would have been celebrating a Labour government."