A senior politician in South Sudan says the south will declare unilateral independence if it does not get a fair referendum on the issue.
Pagan Amum, the secretary general of the Sudan People’s Liberation Movement, said the governing National Congress Party was trying to obstruct the vote.
He said the NCP was insisting that 75% of southerners vote for independence before the south could leave Sudan.
The NCP has not commented on the voting majority needed in the 2011 poll.
“We are warning the National Congress – we are also alerting the people of southern Sudan – that we have a serious problem,” Mr Amum told the BBC World Service’s Focus on Africa.
“The National Congress is poised to betray the people of southern Sudan again.”
“We are not threatening anything at all,” he said. “We are saying that any attempt to deny the people of southern Sudan the right to self-determination will force the people of southern Sudan to declare a unilateral independence.”
‘Simple majority’
Asked why he objected to the 75% figure being used and if he was afraid he could not reach that target, Mr Amum said: “We are not afraid of anything.”
“We are saying the referendum should be a simple referendum like all referendum that have been conducted in the world. They have always been conducted with a simple majority.”
There has been a delay in passing the law which will establish the procedures for the referendum.
The BBC correspondent in Khartoum, James Copnall, said Mr Amum’s comments – and maybe even the NCP’s reported demands for the 75% threshold in the vote – can perhaps best be understood as part of the tough negotiations around this issue.
The south is considered likely to vote for independence when the referendum does take place.
Many of Sudan’s lucrative oilfields are in the south and this, along with national pride, means the north is keen to hold on to the vast if underdeveloped territory.
The 22-year war between the mainly Muslim north and the Christian and animist south ended in 2005, after 1.5 million people died.
Under the 2005 peace deal the former rebel Sudan People’s Liberation Movement (SPLM) formed a power-sharing government with President Omar al-Bashir’s National Congress Party in Khartoum.
National elections are due in 2010, a year before the referendum on whether the south should secede.