Thousands of people gathered in London and other cities around the world on Wednesday to commemorate British lawmaker Jo Cox, who’s killing shocked the country amid a fiercely contested campaign over the future of Britain in Europe.

Artists, friends and family members took to the stage in Trafalgar Square, a mile from the parliament to praise her, as they described Jo, “a passionate campaigner for the rights of women and refugees”. Among those paying tribute were, Nobel Prize winner Malala Yousafzai, the actors Gillian Anderson and Bill Nighy, singer Lily Allen and Cox’s husband and sister.

Brendan Cox said his wife campaigned for the Britain, to remain in the European Union, had died because of her belief, “Jo’s killing was political”, but those beliefs must live on. He said to the crowd, “She just wanted people to be happy and the world to be a better place,” His voice was faltering at times while saying, it was an act of terror designed to advance an agenda of hatred toward others. What a beautiful irony it is that an act designed to advance hatred has instead generated such an outpouring of love. She feared the consequences of Europe dividing again”

Cox was shot and stabbed to death by a man who later gave his name in court as, “death to traitors, freedom for Britain.” Cox’s killing had shaken Britain and triggered a three-day pause in campaigning for a referendum, on Thursday in the country’s EU membership.

US President on Wednesday offered a heartfelt tribute to Jo, hailing the remarkable life of a woman who volunteered in his campaign in 2008. He said in a tribute published in facebook, “Jo knew that our politics, at its best, still works — that, if we recognize our humanity in each other, we can advance the social justice, human dignity and peace that we seek in the world, She gave her time and passion to a country that was not her own because she believed in an idea that transcends borders and cultures — the power of people to bring about change, from the grassroots up,”

By Prakriti Neogi