A petition calling for Article 50 to be revoked and the UK to remain in the EU enjoyed the fastest rate of new signatures on record, the official parliamentary petitions committee said, as the figure surpassed three million.
The website repeatedly crashed on Thursday as millions registered their support for Brexit to be cancelled.
By Friday the petition had reached three million signatures, having attracted more than two million in the space of 24 hours.
The petitions committee, which monitors requests on the parliament website, tweeted that the rate of sign-ups was “the highest the site has ever had to deal with and we have had to make some changes to ensure the site remains stable and open for signatures and new petitions”.
At one point it said nearly 2,000 signatures were being added every minute.
Huge demand persisted into the evening, with the committee tweeting shortly before 7pm that the website was experiencing another spike in new signatures.
It warned that the huge amount of traffic meant some validation emails, which contain a link that must be clicked on to confirm a person’s signature, were taking as long as 24 hours to reach inboxes.
As the number of signatures continued to grow, Theresa May was asked whether she thought the public's view had shifted.
But the prime minister appeared to rule out a change of course, instead pointing to the 2016 referendum as the “biggest democratic exercise in our history”.
MPs may yet be given a chance to debate the petition, however, as it has passed the 100,000-signature threshold.
A House of Commons spokesman said: "We know that the petitions website has been experiencing problems due to the number of people using the site.
"This is a mixture of people signing petitions and refreshing the site to see changes to the number of signatures.
"The majority of people are now able to use the website and we and the Government Digital Service are working to fix any outstanding problems as soon as possible."
EU leaders have said Brexit could be delayed from 29 March to 22 May – but only on the condition that MPs vote for Mrs May's deal next week
