Lewisham East MP Janet Daby has announced she will step down from Lewisham Council to focus on being an MP.
Councillor for Evelyn ward, Alex-Feis Bryce, has also announced his resignation after one year as a councillor.
Ms Daby, who was the cabinet member for community safety for six years, was elected in Whitefoot ward in 2010 and is the founder of foodbank Whitefoot and Downham Community Food Plus Project.
The announcement comes nine months after she was elected to Parliament.
She said: “It has been such an honour and privilege to serve Whitefoot ward as a local councillor for the past nine years.
“I have come to know so many passionate residents and dedicated community leaders who genuinely care about others. I value them and appreciate all that they do.
“Whilst it is now time for me to give up my local council role, I will continue to represent them and all Whitefoot ward residents to the best of my ability as their Labour MP in the Houses of Parliament,” she said.
A Lewisham Labour spokesperson said Mr Feis Bryce had recently become a chief executive of a national human rights charity and could “no longer dedicate the time to being an effective councillor.”
Mr Feis Bryce said: “I am grateful to have been given the chance to represent the people of Evelyn Ward for the past year. Being a councillor is a rewarding but also a challenging experience.
“I hope that I have made a difference by helping those who need a voice to get access to the services they deserve.”
Lewisham Lib Dems have announced they will put forward candidates in both wards to “end Lewisham’s status as a one-party state and to challenge the complacency of the Labour administration.”
Leading anti-gangs advisor Gwenton Sloley has also announced he will stand in the Whitefoot by-election for Lewisham People Before Profit, pledging to give a percentage of the councillor’s allowance to a charity if he wins.
Speaking on her election night last June, Ms Daby said there would be a “significant” period of time before she stood down from the council, she did not want voters to be “weary” heading to the polls so soon after the local elections.
Both by-elections will take place on May 2.
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