The Sudanese government has released results from a national census that will be a crucial component in organizing elections for next year.  But the main party from the country's south has rejected the results.

According to the official results from the census, conducted last year, Sudan's population is just more than 39 million.  Roughly four-fifths of the population lives in the north, according to the survey, and 21 percent in the south.

But the Sudan People's Liberation Movement - former rebels who control the semi-autonomous southern government and share power with the northern National Congress Party at the national level - have rejected the results.  The party says the census undercounts the number of southerners in the country, and overstate the numbers for some northern groups seen as sympathetic to the National Congress Party.

SPLM spokesman Yien Matthew says officials from the semi-autonomous Government of Southern Sudan have raised a number of objections to the results from the north, and have asked to review the paper trail, a request the national government has denied.

"On behalf of the SPLM, I announce our clear rejection as to the results announced officially.  The regional census bureau, that is of government of South Sudan, asked the national census bureau to give them some of the forms or look to the technical parts of the census.  The SPLM is asking why is it that this was rejected," Matthew asked.

According to the SPLM, the population of South Darfur state, part of the North, is much higher than expected, especially considering the area has experienced war for much of the period since the last census.  In addition the numbers for nomadic Arab populations along the North-South border, a group that has tended to support the North in disputes with the South, is higher than the SPLM thinks it should be.

And the number of southern Sudanese living in northern Sudan, many of them displaced during the two-decade civil war that ended in 2005, is far too low, according to the SPLM.  Matthew says the United Nations and other humanitarian agencies have provided estimates for southerners living in the north that are much higher.

The SPLM has said it believes that southern Sudan represents at least one third of Sudan's population.

Lower figures could decrease the South's weight in the arrangements established by the 2005 Comprehensive Peace Agreement, that governs power-sharing and the distribution of the country's oil-wealth.

Continued disagreement over the results could lead to further delays in the national elections scheduled for February of next year.  Elections were originally scheduled for this year, but were delayed to allow more time for preparations.

Matthew notes that two of the main reasons for the delay - the lack of census results and disagreements over the demarcation of the North-South border - remain unresolved. 

Matthew says the National Congress Party appears to be trying to delay the elections, fearful of losing in a free and fair contest.  The North has said it is committed to holding fair elections on time.

Matthew says the release of the results over southern objections is only one instance of the NCP ignoring its obligation to share power with the SPLM under the CPA.

"In so many things they will do things without even consulting the SPLM.  They evacuated the humanitarian organizations without our knowledge, and they are continuing breaking and violating the CPA," Matthew said.

The census is also a necessary step in organizing a referendum in 2011 on whether southern Sudan - currently a semi-autonomous region - will secede from the north.