Tens of thousands of protesters have taken to the streets of central London against President Donald Trump’s four-day visit to the UK, pouring into Trafalgar Square for a mass rally attended by Labour leader Jeremy Corbyn.

“Say it loud, say it clear, Donald Trump’s not welcome here,” chanted the vast crowd over and over as they marched through the capital, snaking through Regent Street.

Organisers of the Together Against Trump mass demonstration claimed they had been told by police that more than 100,000 protesters had joined the march by mid-afternoon.

“Dump Trump”, “atrocious POTUS” and “not on our soil” were among the anti-Trump messages visible in a sea of protesters holding placards as they marched to attend a larger rally in Trafalgar Square.

“Trump wears poorly tailored suits,” proclaimed one sign. Another stated: "Overcomb Brexit."