LONDON, United Kingdom (AFP) — Murdered British MP Jo Cox’s family were to mark what would have been her 42nd birthday Wednesday with an emotional river tribute and a rally in London on the eve of Britain’s European Union referendum.

The commemoration in the city’s central Trafalgar Square is set to include Nobel Peace Prize winner Malala Yousafzai with similar events to take place later in cities around the world, among them Beirut, Nairobi, New York and Paris.

Irish rockers U2, who worked with Cox on the Make Poverty History campaign, have recorded a special musical tribute from Los Angeles which will be broadcast to the crowd in London.

Cox was shot and stabbed in the street on Thursday in her Batley and Spen constituency in Yorkshire, northern England, where there will also be a commemoration with her sister Kim Leadbeater.

The murder of Cox, who was campaigning for Britain to stay in the European Union and was a major advocate for refugee rights, shook the referendum campaign and sent shock waves around the world.

The commemorations began less than 18 hours before the polls open in Britain’s closely-contested referendum on whether it should stay in the EU or leave.

Widower Brendan Cox, in his first interview since his wife’s murder, said he thought she was murdered due to her political beliefs.

“She was a politician and she had very strong political views and I believe she was killed because of those views,” he told BBC television.

– ‘Worried about the tone’ –

“I think she died because of them, and she would want to stand up for those in death as much as she did in life.”

He also said she had “worried” about the tone of the EU referendum debate — “the tone of whipping up fears and whipping up hatred potentially”.

Hers was the first murder of a British lawmaker since 1990 when Ian Gow was assassinated by Irish Republican Army paramilitaries.

Thomas Mair, 52, has been charged with Cox’s murder.

On his first appearance in court on Saturday, he gave his name as “Death to traitors, freedom for Britain”.

A psychiatric report was requested.

Cox and her family, including five-year-old son Cuillin and three-year-old daughter Lejla, lived on a converted barge moored on the River Thames, close to the Tower of London.

A boat carrying her family is due to sail upstream from their houseboat community towards the Houses of Parliament ahead of the commemoration in nearby Trafalgar Square.

Leaders of various faiths were also to lay 42 white roses to mark what would have been her birthday, and the band that played at Cox’s wedding were to perform.

Her life will also be celebrated at the Glastonbury music festival on one of the stages.

A fund created in Cox’s memory by her friends and family has raised more than £1.25 million ($1.83 million, 1.62 million euros) for charities close to her heart, following more than 37,500 individual donations.