The Southern African Development Community's organ on defence and politics, or the Troika, was scheduled to meet in Maputo, Mozambique Thursday to discuss the political situation in Zimbabwe and other regional hot spots ahead of the ordinary summit Friday.
South African President Jacob Zuma, the outgoing chairman of the troika was expected to table a report on Zimbabwe, a day after meeting the unity government principals in Harare.
The same report will be tabled before the 15 regional leaders meeting in summit Friday.
President Robert Mugabe, Prime Minister Morgan Tsvangirai and Industry Minister Welshman Ncube, leader of a rival MDC faction, backed by their negotiators were to attend the troika meeting.
Sources privy to the Zuma report say he will note progress in the passing of the electoral and human rights bills, but will also highlight the latest political logjam on the draft constitution.
Mr. Zuma spent the better part of his Harare consultations Wednesday trying to find common ground on the constitution.
His aide, Lindiwe Zulu, told Studio 7 that while there are still some outstanding issues, Zimbabwe is making steady progress.
The two MDC formations are pushing the adoption of the draft by all the three ruling parties but President Mugabe's Zanu PF is holding out, proposing a raft of changes.
For instance, the party wants dual citizenship removed and gay rights unequivocally outlawed. it is also opposed to the revamping of the courts and the attorney general's office.
Human Rights Watch called on Sadc to press Harare to address rights abuses, security sector reform, accountability for past abuses, and political violence, among other issues.