Nearly 80,000 names have been struck off a petition calling for a second EU referendum after they were found to be fraudulent.
The online petition has been signed more than three million times even though a leading expert suggests it will not have any effect.
The House of Commons Petition Committee said it had removed about 77,000 signatures which were added "fraudulently" and it would monitor for suspicious activity.
Helen Jones MP, the chairwoman of the committee, said: "We take fraud in the petition system very seriously, because it undermines the process of parliamentary democracy.
"People adding fraudulent signatures to this petition should know that they undermine the cause they pretend to support."
She added the committee would meet next week to discuss whether MPs will debate a possible second public ballot.
Thursday's referendum saw 17.4 million, or about 52 per cent, of votes cast to leave the EU, compared with 16.1 million, 48 per cent, for remaining part of the bloc, with a turnout of 72.2 per cent, according to the Electoral Commission.
In response, the online petition has called for the Government to implement a rule that "if the Remain or Leave vote is less than 60 per cent based on a turnout less than 75 per cent, there should be another referendum".
