Petition for second EU referendum reaches 4 million as hundreds attend anti-Brexit protest in London

Originally launched in May, the page has seen an influx of signatories since Friday, as those unhappy with the referendum result seek to overturn it.

The campaign is more than double the size of a 2007 petition urging the Government to abandon plans for pay as you go road pricing which attracted 1.8 million signatures.

 The petition for a second EU referendum has also gathered far more names than one calling for the meningitis B vaccine to be given to all children, which was signed by more than 820,000 at the beginning of 2016, and one seeking to block Donald Trump from the UK after he called for a "total and complete shutdown of Muslims entering the United States", which had almost 600,000 supporters at the end of last year.

On Thursday 51.9 per cent of votes were cast to leave the EU, versus 48.1 per cent for remaining part of the bloc. The national turnout for the referendum was 72.2 per cent, thereby meeting both conditions of the petition.

However, the narrow win masked regional discrepancies which saw majorities in favour of remaining in the EU among voters in Scotland, Northern Ireland and London.

Many of those signing the petition demanding a referendum re-run come from major cities.

However, it emerged on Sunday that parliamentary authorities had removed around 77,000 allegedly fake signatures from the petition - with hackers taking responsibility for adding thousands of counterfeit names.

Signatories were recorded in places as far flung as North Korea, the Falklands, Bermuda, China and Venezuela, and there have been suggestions computer coders may have used special scripts to generate fake signatures automatically.

On Tuesday, a pro-EU rally held outside the Houses of Parliament and in Trafalgar Square attracted hundreds of supporters with banners.

Earlier, David Cameron arrived in Brussels to enter talks with EU leaders. The European Parliament has urged Britain to immediately trigger the divorce process from the European Union, known as Article 50.

EU nations acknowledge the political chaos in the UK but they want Article 50 triggered as soon as possible to calm markets and reassure European citizens.

The "will expressed by the people needs to be entirely and fully respected, starting with an immediate activation of Article 50," said a resolution approved by MEPs at an emergency session, by 395 in favour to 200 against, with 71 abstensions.

It is up to the British government to invoke Article 50 of the Lisbon Treaty that starts the clock on two years to negotiate the terms of the exit.

David Cameron, the Prime Minister, has signaled that Britain might not trigger the exit clause until October.

Already one senior Labour MP, David Lammy, has urged fellow MPs to ignore the result of the EU referendum which he said was advisory rather than binding on Parliament.

On Twitter he wrote: "We can stop this madness and bring this nightmare to an end through a vote in Parliament. Our sovereign Parliament needs to now vote on whether we should exit the EU.

"The referendum was was an advisory, non-binding referendum. The Leave campaign's platform has already unravelled and some people wish they hadn't voted to Leave.

"Parliament now needs to decide whether we should go forward with Brexit, and there should be a vote in Parliament next week.

"Let us not destroy our economy on the basis of lies and the hubris of Boris Johnson."

Meanwhile a second petition, urging Sadiq Khan, London’s mayor, to declare the capital’s independence has topped 175,000 signatures.

Set up by James O’Malley, it reads: “Let's face it - the rest of the country disagrees. So rather than passive aggressively vote against each other at every election, let's make the divorce official and move in with our friends on the continent.

“This petition is calling on Mayor Sadiq Khan to declare London independent, and apply to join the EU - including membership of the Schengen Zone (Umm, we'll talk about the Euro...). Mayor Sadiq, wouldn't you prefer to be President Sadiq? Make it happen!”