Emotional tributes were left in Parliament Square to remember Jo Cox, the Labour MP for Batley and Spen who was killed on Thursday.
Among those who laid flowers and paid their respects were Labour party general secretary Iain McNicol and John Cryer MP.
One message read: "Refugees welcome. Jo: we'll keep up your fight for the better world you believed in."
Another said: "Thank-you for all you did for Syria, for humanity. We will unite against hatred."
Cox was a vocal advocate for the victims of the Syrian civil war. She was co-chair of the Friends of Syria All Party Parliamentary Group, and abstained from the vote on Syrian air strikes, calling for a more ethical solution to the problem.
The mother of two was shot and stabbed outside her constituency advice surgery in Birstall, West Yorkshire.
She had been an MP for just over a year, after being elected in last year's May general election.
Messages from the United States and Germany were among the growing numner of tributes, and pens were left for those gathered to write their own.