Efforts to end the crisis in Zimbabwe suffered further blows at the weekend as the main opposition leader spurned mediation talks and the government stepped up intimidation of opponents.

Morgan Tsvangirai, leader of the opposition Movement for Democratic Change and the victor in March’s first round of presidential elections, rejected an invitation to talks from President Thabo Mbeki of South Africa, who is leading much-maligned regional efforts to broker a deal between Mr Tsvangirai and his arch foe, President Robert Mugabe.