Tens of thousands of people are marching through central London to call for a “final say” vote on Boris Johnson’s new Brexit deal.
Organisers of the “People’s Vote” campaign say they want to check that the UK is happy to leave the EU under the terms negotiated by the PM.
Protesters will head to Westminster as MPs debate the new deal in the Commons.
The march, which began at midday, started on Park Lane and will end in Parliament Square.
Ali Lothian, 60, and Mettje Hunneman, 49, travelled from Dundee and Edinburgh respectively overnight to join the protest.Ali told the BBC she feels it is the last chance to show how strongly she feels about having another vote.
She said: “It’s a big commitment – it’s a whole weekend. But I regretted not coming last time. This time it was a no-brainer.”
Mettje said the fact Parliament is sitting as well makes it “a momentous day”. “I would not feel comfortable sitting at home – I’ve got pals who have got a gig tonight but I just couldn’t be there.”
Millie Bishop-Morris, 17, made the journey from Plymouth with her mum and boyfriend.
“I think it’s important that young people should be angry about this as well,” she said.
“I just think Brexit has gone completely the wrong way. I want to be optimistic but I’m preparing myself for the worst.”
One group of protesters were seen pulling a float depicting top aide Dominic Cummings using Mr Johnson as a puppet.
With “Demonic Cummings” splashed across its forehead, the figure on the float appears to be wearing a Nazi uniform, including an armband which reads Get Brexit Done, and has a Union Jack moustache.
At the scene
By Katie Wright, BBC News
It was deja vu for many people as they descended on the streets of central London once again to demand a final say on Brexit.
Six months on from the last big rally, there was bright sunshine and blue skies to greet the protesters – which included many returning faces, as well as those marching for the first time.
In March a carnival vibe had accompanied the slow walk from Park Lane to Parliament Square, but university student Ben Stocks said the atmosphere this time was “more sombre”.
Another member of the crowd, Simon Gosden, 63, agreed, saying: “There’s more of an air of tension. We know we’re getting down to the nitty gritty – it’s all or nothing.”
One of the new faces included 17-year-old Millie Bishop-Morris, from Plymouth, who wasn’t able to vote in the 2015 referendum but was keen to have her voice heard now.
Another, Ali Lothian, 60, travelled down from Dundee overnight as she thinks it’s “the last chance” to show how strongly she feels about having another vote.
As of Saturday morning, more than £500,000 has been donated to support the protest, and cross-party politicians are calling on people to get involved.
‘Honour democratic values’
People’s Vote organisers are also asking people to sign a letter to Boris Johnson, EU leaders, MPs, and MEPs, asking them to allow “the chance to check whether we want to proceed with Brexit”.
In an email to supporters this morning, Shadow Brexit secretary Sir Keir Starmer said the letter “asks them to honour our shared democratic values, it asks them not to turn away from us now and deny us the chance for a final say.
“Add your name to the letter now and send a message to the powerful.”
Meanwhile, Brexit supporters are due to take to the streets in Manchester on Saturday.
The “march for democracy”‘ will take place near Manchester Cathedral, organised by Leavers of Greater Manchester.
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