Britain's Prime Minister Theresa May leaves after giving a news briefing in Brussels, Belgium March 22, 2019.
An extension could continue for several more months if Britain agreed to vote in May's European Parliament elections. After listening to the prime minister, he said, he had cut his estimate - to five percent.
If May is unsuccessful in getting her deal through Parliament, then that delay will only be until April 12, where lawmakers will then face the choice of either leaving without a deal, approving some sort of new or alternative deal, or revoking Article 50 - the mechanism that triggers Britain's departure from the bloc.
But by Thursday morning the website kept crashing as hundreds of thousands of people signed up demanding to show their disapproval of the Prime Minister and their desire to remain part of the EU. "And I will make every effort to ensure that we are able to leave with a deal and move our country forward".
Mr Russell-Moyle blamed the Prime Minister for having "whipped up fear and division with her speech last night", while Labour frontbencher Angela Rayner said the incident in Brighton was "terribly worrying".
At the first day of the summit, European Union leaders quizzed May for nearly two hours about her plans in case MPs reject her deal, already backed with additional European Union assurances, in a third possible vote next week, as the "feeling in the room was that the likelihood of a positive vote is very small", an European Union official said.
"The 12 April will be a key date in terms of the United Kingdom deciding whether to hold European parliamentary elections".
Diplomats said some of the harder brinkmanship from the continent should be seen partly as meant to pressure British members of parliament to back Mrs May's deal or face chaos.
A notice on Parliament's petitions site. Screenshot Katie Collins
If accepted, it gives pro-EU forces valuable time to mobilise and seek to soften the Brexit deal or attempt to force an election or a second European Union referendum.
The EU-27, however, managed to keep all options open by passing the Brexit "hot potato" back to London, which will now have to decide between a deal, no deal, a long extension with EU elections or revoking Article 50.
European Commission head Jean-Claude Juncker said the EU had done much to accommodate Britain and could go no further. "They have hard jobs to do".
"If that doesn't happen, and if Great Britain does not leave at the end of March, then we are, I am sorry to say, in the hands of God", he said.
Any extension to Article 50 must be decided unanimously by the EU27 and the member state concerned.
"We can not overstate the gravity of this crisis for firms and working people", said the letter signed by Carolyn Fairbairn, director general of the Confederation of British Industry, and Frances O'Grady, general secretary of the Trades Union Congress.
Speaking to German MPs ahead of the summit, Mrs Merkel stressed "the most important emergency measures" are in place in her country to handle no-deal, but she still hopes to avoid a crisis.
Her comments came after the Commons Deputy Speaker Sir Lindsay Hoyle emailed MPs on Wednesday - before Mrs May's address - advising them to travel by taxi or with colleagues amid heightened tensions in the run up to next week's votes.
"One of the things I wanted to use this debate for was to remind people that the 48 percent feel strongly too", said MP Daniel Zeichner of Cambridge, when he raised the subject for debate.
'Cancel Brexit' petition passes one million signatures
A petition calling for the United Kingdom to remain in the European Union is attracting almost 2,000 signatures every minute. May formally made the request for an extension to the end of June in a letter to EU President Donald Tusk on Wednesday.