6.35pm: Vince Cable (Deputy, and now Acting, Leader) and Simon Hughes (President of the Party) have just given a statement outside Cowley Street, confirming that Ming has decided to resign with immediate effect. Ming won’t be making a statement tonight. Hughes said:
"Throughout all his political life Ming has taken all his decisions, and this decision is one of them, in the interests of our party and liberal democracy in Britain."
They didn’t take any questions (ignoring "did you wield the dagger, did you wield the dagger?!").
6.45pm: He apparently told Party officials that he felt he wasn’t able to turn their fortunes around and as there won’t be an election for some months he thought it was time to give way. Shirley Williams says it’s time for a new generation.
6.50pm: Both Lembit Opik and Lord Steel have made accusations about ageism.
6.55pm: Gordon Brown has released a statement saying Ming is "A man of great stature and integrity who has served his party and country with distinction".