Spencer Pratt Claims He Has Recording That Will Force Mayoral Candidate to Resign

Spencer Pratt's out of the Los Angeles mayor's race ... but he's not fading quietly into the abyss ... instead, he's threatening to take down one of the other candidates for mayor ... and he says he has a shocking recording that will make one of them resign.

The reality TV star makes the shocking claim in a new social media post ... a 3-minute clip where he vows his war against corrupt politicians in L.A. is only just beginning, even though his mayoral campaign is over.

Spencer says he has a recording he was saving for the general election, but now that he hasn't advanced ... he says he's going to wait to share it until after Nithya Raman or Karen Bass wins.

He claims the video shows one of the "exalted candidates doing and saying something that would make her resign in shame." He also hints it may have been recorded by one of their staff members.

Spencer also takes aim at Jimmy Kimmel ... and says he's not leaving town.

Jimmy jokingly rented Spencer a U-Haul after he said on the campaign trail he'd leave L.A. if he didn't become the city's next mayor ... but it looks like Spencer's more focused on politicians than late night hosts in his mission to save L.A.

Spencer says he's going to go even harder than before after he didn't make it into the mayoral run-off. He finished the primary in third place behind Raman and Bass, but says he doesn't have to worry about being politically correct anymore.