LONDON - Tens of thousands of people marked the second anniversary of Britain's EU referendum Saturday with a march through London.

The march from Pall Mall to Parliament Square was to back growing demands for a so-called people's vote on the final Brexit deal British Prime Minister Theresa May makes with Brussels.

At the head of the march was World War II veteran Stephen Goodall aged 96.

Leading politicians and Remain campaigners were also at the front of the march, with some people booing as the procession passed close to Downing Street, home of May.

Organisers, the People's Vote, said people must make their voices heard, with speeches in London backing the call for what would amount to a second referendum on a deal. Early estimates put the number of marchers at 50,000, but organisers said it had swollen to double that as more joined in the protest.

The anniversary was also marked by articles in major national newspapers by leading Brexit-supporting senior ministers, insisting Britain would be prepared to walk away without an agreement if a future deal could not be made with EU negotiators.

In the referendum on June 23, 2016, more than 17.4 million people backed Britain ending its membership of the EU, with 16.1 million backing remain.

Britain's International Trade Secretary Liam Fox said the government was not bluffing about being prepared to abandon trade talks. Speaking on the second anniversary of the referendum, Fox said it was essential the EU believed Britain was serious about the threat to walk away from negotiations with Brussels.

Writing in the Sun newspaper, British Foreign Secretary Boris Johnson said: "Across the country I find people who, whatever they voted two years ago, just want us to get on and do it."

Johnson added people didn't want a half-hearted, half-in, half-out Brexit in a political no man's land, with no more British ministers round the table in Brussels, but still forced to obey EU laws.

"They want this government to fulfil the mandate of the people and deliver a full British Brexit," he said.

On the streets of London there was an opposite message as speakers were cheered as they called for a public referendum on a final deal.

Supporters of remain used announcements Friday by Airbus and BMW about their willingness to stay and invest in Britain amid the uncertainty around the future EU trade deal.

Men, women and children from all parts of Britain converged on the capital to take part in the march and rally, many waving EU flags and carrying pro-remain banners.

Co-organiser James McGrory from Open Britain, said: " The most important thing is that this isn't decided just by 650 politicians in Westminster... Brexit is such a big deal that should include all 65 million of us in the country, and that's why people today are marching for a people's vote."

Media reports quoted Leo Buckley, 16, saying: "Brexit has stolen my future. It is stealing it economically...I will struggle to find employment and be worse off when I do."

Meanwhile German medical doctor Horst-Dieter Haas, who has worked for the British NHS since 2005 told reporters he will quit Britain if Britain exits the EU.

Among the speakers were Gina Miller, who successfully campaigned in the highest court in Britain to ensure talks on leaving the EU could not be triggered without the approval of Parliament.

She was cheered as she told the crowd: "We have a right to have our voices heard, it is our right to have a meaningful say on the future."

Meanwhile the Daily Telegraph reported Saturday a new YouGov poll showing that two years on from the referendum the public are still as finely split on the decision to leave the EU as they were in 2016.

Polling from YouGov shows that 46 percent of the public believe that leaving the EU was the wrong decision, while 43 percent think that it was the correct decision.