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 (51.9%) votes cast to leave the EU, compared with 16.1 million (48.1%) for remaining part of the bloc, with a turnout of 72.2%, 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% based on a turnout less than 75%, there should be another referendum".
The petition's creator, William Oliver Healey, has claimed he started the petition a month before the vote because he thought the public would vote to stay in the EU.
In a post on Facebook, Mr Healey, a member of the English Democrats, said: "This petition was created at a time (over a month ago) when it was looking unlikely that 'Leave' were going to win, with the intention of making it harder for 'remain' to further shackle us to the EU.
"Due to the result, the petition has been hijacked by the remain campaign.
"I have been opposed to the bureaucratic and undemocratic nature of the European Union as an institution privately for many years and for all of my political career. I have openly and actively lent my support to both Vote Leave and Grassroots Out campaigns - why would I do this if I wanted to remain in the EU?"
Britain's foremost elections expert, Professor John Curtice, said the petition was likely to come to nothing.
He told the Press Association: "It's no good people signing the petition now, they should have done it before. Even then, these petitions don't always mean a great deal.
"It has passed the 100,000 mark for it to be debated in Parliament. All that means is that some MPs will say, 'It's a terrible shame', others will say, 'Hallelujah'. Then that's the end of it."
More than 160,000 people also signed a separate petition on the Change.org website, calling on new London mayor Sadiq Khan to declare the capital independent from the UK and apply to join the European Union.