Cape Town – A meeting of the Southern African Development Community (SADC) Organ on Politics, Defence and Security Co-operation is expected to kick off in Gaborone on Thursday to discuss the political developments in Zimbabwe.In a statement, the presidency said that the meeting would be attended by ministers from Angola, Zambia, Tanzania and South Africa."It [the meeting] will be co-chaired by the minister of international relations and co-operation of South Africa and the Angolan defence minister. It is expected that the ministers will make recommendations to the heads of state and government on the political situation in Zimbabwe," read the statement. President Jacob Zuma, who is the current chair of the regional body, on Wednesday denounced any unconstitutional takeover of government in Zimbabwe.Zuma said that SADC stood ready to assist in the political impasse currently gripping the country."Presidency has called for calm and restraint and has expressed hope that developments in Zimbabwe would not lead to unconstitutional changes of government as that would be contrary to both SADC and African Union positions," the presidency. President Robert Mugabe and his wife Grace on Thursday remained under heavy guard after soldiers cordoned off the parliament building and the defence headquarters as the security situation deteriorates in the southern African country.Political tensions within Zanu-PF exploded after Mugabe fired his vice president Emmerson Mnangagwa. It followed numerous attack of Mnangagwa by the first lady who was said to be eyeing the presidency ahead of the Zanu-PF congress in December.