This story has been developing over the past few days, so keep your eye on Sudan:
President Omar al-Bashir’s party has said the referendum on whether south Sudan should secede cannot take place until the internal border is decided.
A vote on a possible new country without a clear border would be a recipe for a new war, the NCP says.
But the former rebels in charge of the south insist the referendum must be held on time.
Hopefully this will not become a deadly game of chicken.