By Dave Burke Jeremy Corbyn is at the United Nations’ top court to support claims that Israel is committing genocide in Gaza. The expelled former Labour leader has branded a landmark court case brought by South Africa a “historic moment for humanity”. But No10 this morning branded the case “wrong and unjustified”. South African lawyers called on judges in the Hague to order Israel to halt its military operation. In a controversial court action they claimed that the latest Gaza war is part of a long campaign of oppression of Palestinians by Israel. Israel vehemently denied the allegations. Mr C…