Cllr Jack Hopkins has been elected as leader of Lambeth Labour Group and is expected to be confirmed as council leader next month.
Cllr Hopkins replaces Lib Peck who is taking a new job at City Hall running London's violence reduction unit.
Cllr Hopkins – who beat three colleagues in the Labour Group election on Monday – said: "I'm delighted and honoured to be chosen to lead this wonderful borough. I can't wait to get started and pick up the great work already being done by this administration.
"I've lived in Lambeth for 15 years and been a councillor here for over 8 years – I know what the borough is all about, the challenges we face and the incredible opportunity here. I am determined to make sure those opportunities reach every resident and that our young people get the best start in life.
"Lambeth is a place of energy, creativity and diversity, with fantastic community groups, an engaged voluntary sector and businesses that want to play their part. As leader, I want to bring Lambeth together and I'm optimistic that we've got the energy and skills to tackle the challenges we face."
Jack Hopkins first joined Lambeth as an officer in 2015, and when the Labour group won power in 2006 he became a policy officer working under council leader Steve Reed.
He has been a councillor in Oval ward since 2010 and joined the cabinet in 2012, covering various portfolios including regeneration, economic development, employment, planning, community safety and culture.
His first cabinet stint included responsibility for Lambeth's dealings with the controversial Garden Bridge which at the time enjoyed the backing of the council leadership.
Having left the cabinet in April 2017, Hopkins spent nearly a year as chief executive of the Night Time Industries Association, the trade body for late night entertainment businesses.
In 2017 Cllr Hopkins also set up a consultancy – Good Planners – to give homeowners wanting to extend their properties advice on dealing with council planning departments.
Cllr Hopkins this week applied to have Good Planners Ltd dissolved and struck off the Companies Hoouse register.
He had been expected to stand down from the council at the May 2018 elections but rejoined the Lambeth Labour candidates list at the eleventh hour.
Having been re-elected in Oval ward, he has served as deputy council leader in the current municipal year.
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