The results of a 'pilot census', conducted in April, are being discussed by a technical committee, which includes the northern and southern institutions in charge, the Central Bureau of Statistics and the Southern Sudan Commission for Census, Statistics and Evaluation.
Technical procedures, the timetable and a review of a politically sensitive question about origin will be reconsidered.
Miriam Bibi Jooma, a researcher with the Institute for Security Studies, based in South Africa, told IRIN the census "is critical to providing benchmark data for power and wealth sharing" under the terms of the Comprehensive Peace Agreement, signed in 2005 between the government in Khartoum and the Southern Sudanese authorities. The results of the census will recalibrate ratios for power and wealth sharing. Southern Sudan was allocated shares in the peace deal on the basis that 28 percent of the whole population live there.
Jooma also pointed out that the census was a prerequisite for nationwide elections planned for 2009 and an eventual referendum on self-determination in 2011.
Timing and mapping
Preparations may not be complete by the 14 November deadline, which is towards the end of the southern rainy season. A European diplomat said the process was "way behind", while an international official added that the November target was "very ambitious", and "the extraordinary challenge of full mapping coverage of all areas during the wet season, and the continued delay in funding, makes a January/February  census much more likely".
Boundaries between the north and south, and of some contested areas, such as Abyei, remain un-demarcated and politically sensitive. Even borders between smaller administrative units in Southern Sudan could be disputed.
However, Majok Bol, an IT officer with the Commission, based in Rumbek, southern Sudan, is adamant the project would go ahead. "We will be ready," said Bol. While admitting that "some areas will not be accessible because of flood", he said the operation was feasible if enough logistics resources, including boats, were made available.
Construction work has only just begun on a new operations centre for the southern census commission in Rumbek, with no piped water, telephone service, mains electricity, sewage or paved roads.
The population of Southern Sudan has never been fully counted in the four censuses since independence in 1956 - previous reports by the central government in Khartoum provided only estimates for the south, much of which was controlled by rebel forces after 1983. Political considerations coloured those estimates, according to Southern Sudanese leaders.
In a recent speech, Southern Sudan President Salva Kiir said: "Our population in Southern Sudan used to be predetermined by those who wanted it to be so for reasons best known to them."
Population estimates for Southern Sudan have ranged from six million to 16 million, Bol said. Demographic estimates for the south were based on long-running polio immunisation campaigns, which counted children under five. Using statistical models, the wider population figure was extrapolated.
Key development planning tool
A successful census "will provide international organisations with representative data" to inform their programming, ideally leading to "a more efficient distribution of aid", Bol said. It will provide "basic information to plan for the future . and the gaps in education, health, and physical infrastructure", he said. Ten questions on an A4 short form will cover age, gender, household composition, place of birth and current residence. But 10 percent of respondents will be surveyed with a much more detailed 'long form', including questions on housing, access to sanitation, economic activity, births and deaths. Questions on assets range from whether a household has a satellite dish to the number of goats it owns.
However, Bol added: "Every census comes with huge political disagreements. No matter how good the census is, someone's bound to complain. All people will not be happy."
Question six of the short census form asks if the interviewee is from the north or south or another country. "People are saying it will provoke some conflict," said Bol. "It's like dividing Sudan in two before a decision is made." The form includes a question about religion, but not about language or ethnicity. A likely compromise, sources say, is that question six will be revised to ask a person's region of origin.
Fifty thousand people will be involved in the census, which will divide the country into a patchwork of thousands of enumeration areas (EAs). GPS units, computers, cars, bicycles and air transport are needed to reach every area. The EAs, sometimes defined by sketch maps, need not match existing political boundaries, but must not overlap, to avoid under- or over-counting.
The pilot census covered five EAs in 10 states in Southern Sudan. Ten EAs were covered with a longer questionnaire. The pilot census used a 'purposefully selected sample', including a mix of different locations and difficult-to-reach areas.
The planned national census is a "huge challenge", an international technical adviser to the process told IRIN. "We are trying to count every single person, but don't have maps of the area . It's a puzzle where you don't have the background picture - and there are no pieces," he said.