Cllr Julie Davies was a "warm, kind and compassionate" councillor who "fought passionately" for the community, young people and teachers.
The 67-year-old, who was cabinet member for communities and civic life at Haringey Council, has died following a short illness.
Politicians and former colleagues today paid tribute after her death was announced.
The mother-of-two had lived, worked and campaigned in Haringey since 1983, and served as a Labour councillor since 2018 when she was elected to represent Hermitage ward.
Before being elected to the council, she worked as an English teacher in Haringey schools, where she also served as branch secretary for the National Union of Teachers.
Her passion for helping young people inspired Cllr Davies to serve as a school governor for five Haringey schools.
In her cabinet role, she led on parks, leisure, culture, libraries, local food policy and active citizenship.
She was also passionate about preserving, developing and celebrating the borough's heritage and civic resources.
Haringey Council leader Cllr Peray Ahmet said Cllr Davies would be "missed by everyone in the council and beyond".
Leading the tributes, she said: “I am deeply saddened by this news. My thoughts, and those of my colleagues, are with Julie’s family and we all want to offer them our sincerest condolences.
“Julie was a hugely knowledgeable, experienced, and effective trade unionist, cabinet member, and advocate for children. But before and above all of that she was a warm, kind, and compassionate person, and a close friend to me and to so many of us in Haringey.
“We are all in profound shock that she’s gone, and will miss her companionship, her acerbic sense of humour, and the immense decency she displayed to everyone whose lives she touched.
“She was truly an unstoppable force, and she will be so deeply missed.”
Tottenham MP David Lammy said in a tweet: "Very sad to hear of the passing of councillor and trade unionist Julie Davies, a great friend who fought passionately for our community, young people and teachers in Haringey.
"She will leave a hole in all our hearts and we send love and condolences to her two boys Harry and Ted.
Hermitage New River Association, a community group in Cllr Davies' ward, said: "This is awful news, our deepest condolences to her family, friends, and colleagues.
"We were absolutely delighted to elect her as our councillor last year, she will be very much missed."
Diana Edmonds, National libraries director for Greenwich Leisure Ltd and a former head of libraries at Haringey, said: "I am so very sorry to hear this. Julie was a committed and dynamic councillor."
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