Councillor Lib Peck has been chosen as the leader-elect of Lambeth council.
It means she will replace Steve Reed as leader of the council. Reed is campaigning to be elected as the MP for Croydon North.
Cllr Peck, a Labour councillor representing Thornton ward, is the council’s cabinet member for regeneration and strategic housing.
She was chosen as leader-elect at a meeting on Monday evening by fellow Labour councillors – beating the other candidate, Cllr Pete Robbins.
Peck tweeted: “It’s an honour and a privilege to be elected as leader-elect of Lambeth Council after an excellent contest with @cllr_robbins”
Robbins tweeted that Peck would be “brilliant” in the role and that she had beaten him “fair and square.”
Peck will remain as leader-elect until she is formally approved as leader by a meeting of the full council, expected to happen in the next few months.
The by-election in Croydon North, in which Reed is standing as the Labour Party candidate, is due to take place on 29th November.
The area is seen as a safe seat for Labour, which won 56% of the vote at the 2010 general election, meaning Reed stands a good chance of being elected. However, if Reed does not win the by-election he would not return to his post as council leader.