LONDON (AFP) - Thousands marched through London on Saturday, waving European flags and chanting "We love you EU" to voice their opposition to Britain's stunning vote to quit the bloc.
The march went past Downing Street - where demonstrators shouted "shame on you" aimed at outgoing Prime Minister David Cameron, who called the referendum - before ending up at parliament.
"Breverse", "The Leave Campaign Lied", "Save our Future" and "Never Gonna Give EU up," were among the colourful banners on display, the latter referring to the 1980s hit by pop star Rick Astley.
Organisers said over 40,000 took part, but police did not give figures.
"I think the Leave campaign misled people, we are (making) a wrong decision because of the lies," protestor Casey, 37, told AFP.
"Baguettes not regrets," chanted others along the route.
In a move that stunned Europe, Britons voted 52 per cent in favour of withdrawing from the EU bloc with 48 per cent against, with many citing immigration concerns as the reason to leave the bloc.
The narrow victory has triggered anger in Britain among those who wanted to remain in the EU and more than four million people have signed a petition calling for another referendum.
"There must be a second referendum. Everybody knows that if there is... we'll vote to stay," said former television producer Nicholas Light, 82, on Saturday's march.
The seismic June 23 vote prompted the resignation of Cameron - who called the referendum in a bid to decide the long-contentious issue once and for all, but backed the failed Remain campaign.
It also unleashed a bitter leadership battle in the ruling Conservative party and chaos in the main opposition Labour party, whose leader Jeremy Corbyn is now facing all-out revolt.
The favourites to succeed Cameron have meanwhile been pushing for a delay in starting the process that will eventually see Britain leave the 28-member EU.
Frontrunner Theresa May and high-profile rival Michael Gove have both said they do not expect Article 50 - the formal procedure for leaving the bloc - would be invoked this year.
EU leaders have urged a swift divorce, fearful of the impact of Britain's uncertain future on economic growth and a potential domino effect in eurosceptic member states.
Last week's shock vote plunged financial markets into crisis, wiping trillions off equities around the world and sending the pound to its lowest point against the dollar in more than three decades.
The Bank of England has said it could slash interest rates this summer to counter the downbeat economic outlook.
And finance minister George Osborne has warned the government would abandon its promise to achieve a budget surplus by 2020, sparking forecasts of more spending cutbacks and tax hikes.
The vote over the EU laid bare serious divisions in Britain.
Younger voters - many of whom worried about their right to travel and work in the EU - mainly voted to remain while their Baby Boomer elders were likelier to vote Leave.
Voters in Scotland, Northern Ireland and the capital London backed remaining, while those that chose to leave were largely from less affluent areas in England and Wales.
The Scottish vote has re-ignited the debate over independence there.
First Minister Nicola Sturgeon went to Brussels Wednesday to press Scotland's desire to remain part of the EU, and says a second independence referendum is now "on the table," after voters voted No in 2014.
A poll for BBC's Newsnight programme found that 16 percent of voters think Britain will stay in the bloc, and 22 percent said they do not know if it will leave.
Queen Elizabeth II, meanwhile, on Saturday urged calm in an "increasingly challenging world," in what some commentators suggested could refer to the situation after the Brexit vote.
"As this parliament has successfully demonstrated over the years, one hallmark of leadership in such a fast-moving world is allowing sufficient room for quiet thinking and contemplation," she said, while opening a new session of the Scottish parliament in Holyrood.
The BBC' Scotland editor said the remarks, the Queen's first since the Brexit vote, could be seen as "a 'Keep Calm and Carry On' message'."
Specifically, they appeared aimed "at the wider body politic, at those in Holyrood, Westminster and elsewhere who now have to cope with the impact of the vote to leave the EU," he wrote.