London Assembly member Keith Prince has revealed he is also planning to stand for election to Havering Council next year.
Mr Prince represents Havering and Redbridge on the body, which is part of the Greater London Authority (GLA), but told the Recorder he will be a Conservative candidate for Squirrels Heath ward at next year's elections.
He lives in the ward and said it was always his aim to return to being a Havering councillor, a role he previously held between 1990 and 1995.
But Havering's Residents Associations (HRA) questioned the move.
The group's deputy chair Cllr Graham Williamson said: “Surely Keith Prince has enough work to do with the GLA? This will severely reduce his capacity to represent the residents in Squirrels Heath ward."
Mr Prince hit back, saying the HRA's viewpoint showed "a lack of understanding" of local government.
He said: "The GLA was designed to accommodate councillors. A large number of current GLA members are councillors.
"It is a real advantage being both (a councillor and GLA member). A lot of the casework I get is council casework. I can deal with it directly myself as a councillor.
"There is no difference to having a job and being a GLA member."
Mr Prince also claimed council leader Damian White had decided to switch ward from Squirrels Heath and stand in Havering Park, which will become Havering-atte-Bower at next year's elections.
When contacted by the Recorder about the mooted move, Cllr White did not respond.
Mr Prince was born in Elm Park and moved to Northumberland Avenue at the age of two, living there for 26 years.
He also studied at Ardleigh Green School and Ardleigh Green College, now part of Havering Colleges.
After serving on Havering Council, he spent 15 years as a Redbridge councillor, including five as council leader between 2009 and 2014.
He was first voted onto the London Assembly in 2016 and was re-elected earlier this year.
Mr Prince said: "I am a Romford boy. This is home for me.
"I want to make sure my ward is the best ward in the borough."
Among his priorities will be to "annoy" council officers on issues such as pavements and rubbish - "the little things that really matter" - as well as homelessness and knife crime.
But he added: "All those things will come but my aim is making sure Squirrels Heath is an area we are proud of."
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