The African Union has warned against holding a referendum, saying such action could increase the risk of violence between the Ngok Dinka and the Misseriya. The Misseriya have warned that a referendum in which they are not participants cannot take place.
The Abyei region is rich in oil, one of the reasons both Sudans are reluctant to give it up. An African Union panel mediating talks between the countries last year proposed a referendum to be held in Abyei this month to determine which country the region would join. The AU proposal said only the permanent residents of Abyei would be allowed to vote in the referendum. That proposal was rejected by Sudan, which does not agree with South Sudan over who should be eligible to vote.
While South Sudan says only the Ngok Dinka should vote, Sudan insists the Misseriya nomads who spend up to six months in the area should also participate. Khartoum has argued against any unilateral action in Abyei, with Foreign Minister Ali Karti saying the dispute can only be resolved through negotiations between the two countries.
According to a cooperation agreement signed last year, both Sudans were expected to set up an interim administrative body in Abyei comprised of representatives from the Dinka Ngok and Misseriya ethnic groups. They were also expected to set up a police force and a legislative council, with the Ngok Dinka taking 60 percent of the seats and the rest going to the Misseriya. However, that plan has stalled amid disagreement over who should chair the council.
South Sudan President Salva Kiir wrote to the African Union recently urging it to do more to end the deadlock over Abyei, saying he saw no possibility of reaching an accord with Sudan anytime soon.
Following a meeting between Sudanese President Omar al Bashir and Kiir in the South Sudan capital, Juba, earlier this week, the South Sudanese government has tried to distance itself from the upcoming vote in Abyei. Michael Makuei Lueth, the South Sudanese information minister, said on Wednesday that his government "has nothing to do with" the referendum.
But Abyei leaders, many of whom are members of South Sudan's ruling party, said they would push ahead with the referendum despite the apparent lack of support from Juba.
"We do not believe that is the position of the government of South Sudan. That is a personal opinion of the information minister," said Edward Lino Abyei, who co-chairs the Abyei Joint Oversight Committee, an administrative body tasked with resolving the Abyei dispute.
Some analysts say the referendum will put pressure on both Sudans and the African Union to do more to end the Abyei dispute.
"The message it sends is that we are frustrated, we have been waiting for a peaceful and speedy resolution of this conflict but it has not happened," said Zachariah Akol of the Sudd Institute, a Juba-based think tank. "They (the Ngok Dinka) also genuinely believe that the resolution of the conflict requires a referendum."