A party leader expressed fears that the 2011 referendum on South Sudan self-determination may be rigged by the supporters of unity within the Southern ruling party.
He added that they are in position to rig the referendum to favour their view.
Mr. Sule said the North wants the referendum to prove that the South wants unity.
He urged southerners to be vigilant and not allow the referendum to be rigged.
Mr. Sule said all parties should be involved in the organization of the consultation.
South Sudan is expected to vote in a referendum on January 9, 2011, on whether to remain as a united Sudan or become an independent nation.