Thousands of people have gathered in London and in cities around the world to commemorate slain British lawmaker Jo Cox on what would have been her 42nd birthday.

Artists, friends and family members took to a stage Wednesday to praise a woman they described as a passionate campaigner for the rights of refugees and women.

Cox was shot and stabbed to death in her constituency Thursday by a man who later gave his name in court as "death to traitors, freedom for Britain."

Her killing shocked Britain and triggered a three-day pause in campaigning for a referendum Thursday on the country's EU membership.

Cox's husband Brendan told a crowd of 9,000 in Trafalgar Square that Cox "feared the consequences of Europe dividing again" and urged people to follow her example.