The Colchester MP Sir Bob Russell has raised concerns over a spoof Twitter account set up in his name.
The Liberal Democrat MP raised the issue in the House of Commons, saying the account has been set up by someone with a "sick, evil and warped mind" to post "vile" comments under his name.
In response the Speaker of the Commons John Bercow said he understood Twitter would promptly shut down spoof accounts set up to impersonate MPs. But he warned he would be prepared to revisit the issue if bosses at the social networking site did not act quickly.
Sir Bob said: "A Twitter account has been set up in the name of Bob Russell MP but I assure you that it is not I that has done so...
"This has involved a spoof YouTube video of me and letters to newspapers with false names and addresses. Mr Speaker, can you guide members about what can be done in case of impersonation of a Member of this House?"
Mr Bercow replied:
"It is clearly unacceptable that you are subject to this form of harassment. It is not however a matter of order for the Chair.
"I understand, however, that the companies which host such accounts will usually respond promptly to any example where 'MP' is used illegitimately. For tonight, I shall leave it there."