Labour leader Jeremy Corbyn, Prime Minister David Cameron and John Bercow, the Speaker of the House of Commons, visited Birstall on 17 June to deliver speeches after Cox's killing in her West Yorkshire constituency of Batley and Spen. Corbyn described Cox, who was elected at the 2015 general election, as an "inspiring" new MP.
"She was brutally murdered on the streets of this village, doing the job she was elected to do, representing the people she was elected to serve, doing her duty to the public and our democracy," the Labour leader said.
He added: "Ours is a country where tolerance and respect for other people and different viewpoints have always been highly valued. We must not allow those who peddle hatred, terror and division to poison and degrade our national and political life.
"Jo Cox stood for tolerance, justice, peace and human rights. If any good can come from her killing it should be for us to come together as a country and face down hatred and intolerance in our society.
"Jo's death is a profound loss for all of us in the Labour party and wider Labour movement, but of course most of all to her close friends, family and her two young children. They will now grow up without their mother, but can be immensely proud of what she achieved and what she stood for. We send them, and Brendan, our deepest condolences and love. They are in the hearts of all of us."
Floral tributes have also been left to Cox on Parliament Square, opposite the Houses of Parliament in Westminster. George and Margaret Aitken, who were in holiday in London from Edinburgh, spoke to IBTimes UK at the site on 17 June.
"We are absolutely stunned by this event, you know, it's just awful," the couple told said, describing their reaction to the tragic news as "utter disbelief".
They added: "It shouldn't happen any time, but why to somebody who is doing good for her constituency. Everybody that's been interviewed at her home constituency has nothing but good to say about her."
Kathryn, another mourner who laid flowers for Cox and declined to give her second name, said: "I'm really saddened by hear death and inspired by her legacy. I think she achieved a lot in a short amount of time and a lot of us could learn from her example."