Ken Livingstone has been suspended by Labour for “bringing the party into disrepute” in the wake of the anti-Semitism row, officials said.
The party is launching an investigation into the former London mayor’s conduct after outraged senior Labour figures lined up to call for him to be kicked out.
Chief whip Rosie Winterton is also hauling backbencher John Mann in for a meeting over his behaviour after he launched a furious face-to-face attack on Mr Livingstone, accusing him of being a “Nazi apologist”.
A Labour spokesman said: “Ken Livingstone has been suspended by the Labour Party, pending an investigation, for bringing the party into disrepute.
“The chief whip has summoned John Mann MP to discuss his conduct.”