Thousands of people have gathered in central London to protest against plans to leave the European Union.
Demonstrators wearing EU flags as capes and with homemade banners saying "Bremain" and "We Love EU" gathered on the streets around Park Lane for the March for Europe rally.
Protesters taking part in the event, which was organised on social media, were due to march through London to Parliament Square.
Comedian and satirist Mark Thomas organised the march to address his "anger, frustration and need to do something". He estimated between 20,000 and 40,000 people would be at the event.
He said: "We would accept the result of the referendum if it was fought on a level playing field. But it was full of misinformation and people need to do something with their frustration."
A cheer went up from the crowd at 11.30am as the marchers set off.
Father and daughter Bill Baker, 59, and Jess Baker, 22, from Islington, north London, had made a banner for the march which read: "I will always love EU."
Ms Baker said: "We didn't want to leave but if you respect the decision of the referendum, which we should, we still want Britain to be EU orientated, outward looking and inclusive."
Philippa Griffin, 40, from Hertfordshire, brought a French stick to celebrate Europe as her alternative to a protest banner.
She said: "I'm absolutely outraged at the way people voted, the lies the referendum was based on and the divide in the country because of it. My ideal outcome from this march is that MPs realise that leaving the EU is not what people truly want. It feels like our country has already changed."
The Met Police said there would be officers at the event to provide "flexible and appropriate" policing.
Marie Sansford, 66, from Brighton, said she was against joining the European Union in the 1970s.
She said: "I feared that joining the EU would allow global companies to take over, which has happened to an extent. But being in the EU we can group together with other countries, be friends with our neighbours. I don't want to see the whole of Europe fall apart. I'm just very worried for future generations."
The March for Europe supporters launched into an impromptu rendition of John Lennon's Imagine, led by a man in the centre of the crowd with an EU flag painted on his forehead, armed with a megaphone and bouncing on a friend's shoulders.
William Dramard, 36, moved from France to Manchester to study 16 years ago. A homemade placard represented his French roots, his Finnish wife, their English bull mastiff dog and the European Union.
The engineer, who travelled to London alone for Saturday's rally, said: "My family exists thanks to the EU. One of the reasons my wife and I came here was because of freedom of movement. We met here and started our life together here. This is what we consider to be our home now."
Genevieve Parke, 34, who is seven months pregnant, marched carrying an EU flag with her two-year-old son Ernest, who was blowing his own crocodile-shaped trumpet.
Mrs Parke, who lives in London but is originally from Fermanagh close to the border in Northern Ireland, said: "Leaving the EU will have a polarising effect on communities at home again. I don't want to go back to a border with guns and checkpoints. That will bring back a lot of horrible memories for people, if nothing else."
Her friend and mother-of-three India Lovett, dressed in a gold sequinned jacket and carrying an EU flag, is also from Northern Ireland.
The 34-year-old said: "The referendum result was absolutely terrifying for Northern Ireland.
"My eldest is 14 and he's really good at French. We had dreams for him to go to university in France. I fear that his future may now be really limited."
Her husband, Dorian Lovett, 34, said: "If Remain had won, Leave would still be campaigning. I think leaving the EU needs more discussion - this was an advisory referendum.
"There needs to be pressure on the Government so they remember that a large number of people don't want to take this course of action."
Mathilda Fell, 14, is marching with her parents. The budding human rights lawyer from London fears her dreams of studying at university in Belgium or Holland might be thwarted by an EU exit.
She said: "I feel really let down that my voice, and the voice of young people, hasn't been heard in the referendum. It's my future that's going to be affected."