May Day rally held in London's Trafalgar Square

Britain's shadow chancellor John McDonnell led a May Day rally in London's Trafalgar Square Monday, calling on people to fight for social problems in the country.

Following several incidents in London recently linked to terrorism, security beefed up around central London, with Trafalgar Square itself ringed by a large number of police officers.

Several thousand trade unionists, representatives from minority groups, austerity campaigners and socialists marched across the British capital from Clerkenwell Road to the famous square, one of London's main gathering points.

The Labour politician described the growing demand in Britain for foodbanks, worsening childhood poverty and low wages as a "bloody disgrace."

With a general election in Britain just weeks away, McDonnell urged the crowd to "seize the moment" and end Prime Minister Theresa May's rule at 10 Downing Street.

During a politically charged speech, McDonnell read a message from Jeremy Corbyn, leader of the main opposition Labour Party.

Corbyn sent "May Day greetings for peace around the world," and "together we can win."

The crowd, many waving banners and placards, responded by chanting "the workers united will never defeated."

A spokesperson for the organizers said, May Day is the day to fight against attacks on the disabled, education and housing, as well as against the anti-union laws, racism, the threats to peace and other areas of lives. Endi