Police are investigating an allegedly threatening tweet in which a user encouraged people to "Jo Cox" an MP.
Anna Soubry, the MP for Broxtowe in Nottinghamshire, was the target of the abuse.
But, she hit back at the twitter user, calling them a "sad cowardly troll".
She also pointed out a spelling error in their tweet, which read "someone Jo Cox Anna Sourby please".
The MP, who was a remain supporter in the EU referendum, added: "This is what has happened to our politics...Tolerance & free speech must prevail."
The account has since been deleted.
It comes a week after Thomas Mair, 43, was jailed for life for shooting and stabbing the Labour MP to death outside her constituency office in West Yorkshire in June.
Nottinghamshire Police said: "We have received reports of threats made to an individual.
The force added that it "takes reports of this nature very seriously and an investigation is under way."