Richmond Lib Dem leader Cllr. Gareth Roberts announced that Cllr. Jennifer Churchill (Teddington ward) left the Lib Dems for Labour on "extremely good terms" and said he would continue to work closely with her on a cross-party basis.
He added: "Though she may no longer be a member of the Lib Dems, I'm sure Jennifer will continue to be supportive of our work as the only local party capable of providing a credible alternative to Nick True's increasingly arrogant and out of touch Conservatives."
Cllr. Churchill, wife of Lib Dem councillor Cllr. Stepen Knight, said she will continue to fight for a better deal from the Conservative council.