However, Johnson accused the Commons inquiry of trying to drive him out. He said in a statement: "They have still not produced a shred of evidence that I knowingly or recklessly misled the Commons."
However, evidence that was provided to the committee in March noted that Johnson had admitted that he misled Parliament. But he has denied doing so deliberately.
Johnson's statement did not specify what sanction the committee suggested.
He said: "I have written to my association in Uxbridge and South Ruislip to say that I am stepping down forthwith and triggering an immediate by-election."
"I am very sorry to leave my wonderful constituency. It has been a huge honor to serve them, both as Mayor and MP."
"But I am proud that after what is cumulatively a 15-year stint I have helped to deliver among other things a vast new railway in the Elizabeth Line and full funding for a wonderful new state-of-the-art hospital for Hillingdon, where enabling works have already begun."