Zimbabwean police raided an opposition office on Thursday night and arrested two western journalists ahead of a critical meeting of President Robert Mugabe’s politburo on Friday. Hardliners at the meeting are expected to oppose doves seeking to persuade Mr Mugabe to concede defeat in last weekend’s elections.

Thursday night’s events tempered a mood of rising optimism among Movement for Democratic Change officials and diplomats, who said earlier that Mr Mugabe could step down within days as he faced pressure from regional leaders and some in his party not to fight on.