The MP for South Cambridgeshire, Heidi Allen, has announced she will not "re-stand when the next general election comes".
Heidi Allen previously quit the Conservative Party to join Change UK. She later joined the Liberal Democrats.
In a letter to her constituents she said: "I am exhausted by the invasion into my privacy and the nastiness and intimidation that has become commonplace."
She added that she had installed panic alarms in her house after "threats, aggressive emails, being shouted at in the street, sworn at on social media".
Heidi Allen's letter to her South Cambridgeshire constituents