The Security Council on Monday was struggling to agree a statement slamming the Zimbabwe violence as UN chief Ban Ki-moon said a planned presidential runoff vote would not be credible and should be put off. Britain, the United States and France meanwhile branded President Robert Mugabe's regime as “illegitimate” in view of the widespread violence and intimidation that forced opposition leader Morgan Tsvangirai on Sunday to withdraw from Friday's vote. And Tsvangirai, who won the first round of presidential voting in late March but failed to secure an outright majority to avoid a runoff, told CNN Monday that the world community should declare the June 27 runoff “null and void” and organize a new vote. The Zimbabwean opposition leader was Monday holed up in the Dutch embassy in Harare as police, some of them in riot gear, raided the headquarters of his Movement for Democratic Change (MDC) party. Ban backed Tsvangirai's stance, telling Harare authorities they should not hold the vote Friday as “it would only deepen the divisions within the country and produce results that cannot be credible.” Saying there was “too much violence, too much intimidation,” Ban described the crisis in Zimbabwe as “the single greatest challenge to regional stability in southern Africa today.” “The region's political and economic security are at stake as is the very institution of elections in Africa,” he said. The 15-member council was meanwhile haggling over whether to hold an open or closed-door meeting to hear UN Under Secretary General for Political Affairs Lynn Pascoe's brief on UN envoy Haile Menkerios' five-day visit to Harare last week. Menkerios, a UN assistant secretary general for political affairs, was in South Africa where he met Friday with South African President Thabo Mbeki, who has been leading efforts by the Southern African Development Community (SADC) to mediate an end to the crisis in Zimbabwe. According to reports, Mbeki is trying to arrange a first-ever meeting between Mugabe and Tsvangirai that would allow for talks on canceling the June 27 balloting with a view to forming a national unity government.