Cllr Christie Lambert announced she has resigned from her role as cabinet member for transport on Southampton City Council.
She confirmed she will remain an elected representative for the Freemantle ward as part of the Labour group.
Cllr Lambert said: “I have made the difficult decision to resign from my role as cabinet member for transport.
“Serving in the cabinet has been an incredible honour, and my love for this city runs deep.
“I came to this country with little-to-no contacts, and Southampton welcomed me with open arms.
“It was here I have raised my children and here where I proudly became a British citizen.
“To go from that moment to serving as a councillor has truly been a dream come true.
“I am incredibly proud of the work we have accomplished together during my time in the Cabinet, but unfortunately, a personal family emergency has recently arisen that requires my full attention.
“However, my dedication to the people of Southampton remains as strong as ever.”
Cllr Lambert, who was first elected in 2023 and retained her seat the following year, said she will continue to serve the city from the backbenches and will remain a steadfast advocate for residents in Freemantle as a Labour councillor.
She added: “I look forward to continuing my work for our local community and supporting the city’s progress in this new capacity.”
Cllr Lambert was appointed to the Labour cabinet in May 2024 with responsibility for communities and safer city.
After Cllr Alex Winning became leader of the council in July last year, a reshuffle saw Cllr Lambert become cabinet member for transport.
On her decision to step down, Cllr Winning said: “Christie has made a valuable contribution to cabinet and has shown real dedication in a demanding portfolio.
“I respect her decision to focus on her family and am grateful that she will continue her work as a ward councillor and as part of our Labour team.”
Cllr Winning will take on responsibility for the transport portfolio as an interim measure until the end of the current municipal year.
Cllr Lambert remains the deputy leader of the Labour group, which is a position voted on by members of the group.
The post is not an executive role on the council, and it has no allowance attached to it.
There is no requirement for the deputy group leader to be a member of cabinet.