Thousands of protesters were in London on Saturday, calling for a vote on any final deal seeing the UK leave the European Union.
But why were the marchers insisting on another say over Brexit?
Before Saturday, Dodo Pearce had never joined a protest in her life. But the 69-year-old decided to travel from South Normanton in Derbyshire to call for a "People's Vote".
"I'm hoping it's not too late, but we have got to take the chance for goodness sake," she said.
"These crowds of people make me emotional. I've seen signs about futures being stolen and it brings tears to my eyes. I want to march and I want a vote."
Her husband, John Pearce, carried a placard saying "grumpy old Brits".
"The first referendum was won on spurious information from both sides," he said.
"Now we know a lot more, I think people have changed their minds, both ways, and deserve a chance to vote."
Cinzia Sangiovanni has lived in the UK for 19 years, and lives in south London with her British husband and two children.
The whole family took part in the march, as three of them hold Italian passports - and she fears for their future without a say on the deal.
"I want to march because I feel my rights are under threat," she said.
"If I was told to, I wouldn't be able to just turn around and go back to Italy. I just worry for the future."
Among the sea of EU flags was Erika Gallacher, who moved from Carlisle to London 11 years ago.
"I have friends who voted a different way to me, but I also have a lot of friends from the EU," she said.
"I work for a university and I'm worried about the students and what will happen to them.
"But for me, I also worry about my future, starting a family and bringing up children. I cannot see any good to it for them."
Leo Buckley was prominent at the head of the march with his placard, reading: "Brexit has stolen my future."
The 16-year-old from Hampshire said: "I think my placard says it all.
"It is stealing it economically - we have already seen the drop in the pound and the loss of jobs - so I will struggle to find employment and be worse off when I do.
"And also socially - look at the rise in hate crime and xenophobia. I don't want Brexit to become the poster boy of a return to attitudes from the 1930s."
A group calling themselves the "Suffolk EU Alliance" were also out in force carrying placards and plastered in stickers stating their cause.
Christine Speer was one of them - originally from Canada, but a British citizen for 50 years who considers herself a "citizen of nowhere".
"The EU has its problems, but there are a number of problems at the time of the referendum that weren't because of the EU - the government was responsible," she said.
"Some people who voted for Brexit will actually find they are worse off.
"Ideally it would be better if Brexit didn't happen, but if it does, the public needs to have a say."
Dr Horst-Dieter Haas proudly carried his German flag as he attended the march.
He married a British woman, but the pair spent 30 years in his home country, bringing up their children, before moving to the UK.
He has been working in the NHS since 2005, but says he will quit if Brexit goes ahead.
He added: "It is already impacting the NHS. We haven't got enough doctors, nurses, physiotherapists, we don't even have enough money, and that will all be worse if Brexit happens.
"The NHS is not performing and there are too many lies about the benefits. I will definitely be stopping if we leave."
The counter march
But as the pro-EU protest reached its rally point in Parliament Square, another was heading in the same direction.
The UK Unity and Freedom march said it was focusing on "freedom from the EU, freedom from terror, freedom of speech, freedom from Sharia law, and unity of all people, irrespective of race or creed".
The pro-Brexit march was significantly smaller, but their voices rang out as they walked along Millbank, with supporters chanting for "our country back" and singing Rule, Britannia!
Shazia Hobbs, who was speaking at the event, criticised those on the opposing protest.
"That march is silly," she said. "We voted to leave so we should leave.
"What do they want, best of three? We voted for Brexit."
One woman, who didn't want to be named, had travelled from Brighton to join the march.
She said: "I'm on this march because I am a patriot. The EU is an undemocratic and authoritarian establishment. We need to be a self-governing nation."
And a man, who also did not want to be named, added: "I don't like big government. That is what the EU is."
Whether either protest will impact the government's next steps is yet to be seen.