Founder of anti-Brexit campaign For Our Future’s Sake Jason Arthur has said that the People's Vote March was about preventing the UK from becoming "poorer and more isolated".
Mr Arthur told talkRADIO: “It is a huge decision that is going to affect our country for decades.
“It is going to be young people who are going to have to suffer the consequences of it if it goes badly and I strongly believe it will do.
“So we are here marching today at the front of the People’s Vote March because we want to make sure that young people’s voices are heard.
“We are marching for jobs, we are going to be marching for the protection of workers’ rights, protection of environmental standards.
“We are trying to make sure that this is a future that people can feel invested in, rather than one that is going to make our country poorer and more isolated.”
More than 500,000 campaigners
This comes as the People Vote’s March organisers claimed more than 560,000 anti-Brexit campaigners joined the march through London calling for a second EU referendum.
The People’s Vote March, also called the March for the Future, set off from Park Lane on Saturday midday and finished at a rally in Parliament Square with speeches from Mayor of London Sadiq Khan and Celebrity Chef Delia Smith.
The People’s Vote campaign said its stewards estimated the crowd to be around 570,000 protesters.
It was originally predicted that the march would be attended by 100,000 protesters calling for a vote on the final Brexit deal.
'This is a historic moment'
Front of the People's Vote March as anti-Brexit campaigners being walking towards Parliament Square, London. Image: Holly Pyne
Mr Khan told the crowd that the People’s March was a “historic moment” and that it was “inspiring” to see so many young people protesting.
He said: “This is a historic moment as people come from all corners of our country and all walks of life.
“People have come together to have their voices heard.”
He added: “It is inspiring to see so many young people leading the way.
“It is their future on the line. Their voices were not heard in the EU referendum but they were heard today echoing all the way down the road to Downing Street.”
Protesters could be heard chanting "Listen up Theresa May, the people want a final say" and "Put it on a red bus, Brexit sucks".
In Parliament Square, videos of Brexiteers Boris Johnson and Jacob Rees-Mogg were booed by the crowds.