South Africa’s President Jacob Zuma has said he will resign “with immediate effect”.
Mr Zuma made the announcement late on Wednesday in a televised address to the nation.
The ANC had been prepared to pursue a vote of no confidence in parliament on Thursday.
The party welcomed Mr Zuma’s resignation after months of growing public anger over multiple corruption allegations.
Mr Ramaphosa is expected to be elected swiftly in a parliament vote and sworn in.
