Thabo Mbeki's departure from office could hardly come at a worse time for the Zimbabwe settlement negotiations, write Tony Hawkins in Harare and William Wallis in Johannesburg .

It appeared likely yesterday that he would retain the mandate - from both the ruling African National Congress in South Africa and the regional Southern African Development Community - to mediate in the talks, at least in the short term. But Mr Mbeki would have less clout, if he were no longer president of South Africa, to break the logjam already threatening to unravel last week's deal.