“Sharia and Islam will be the main source for the constitution, Islam the official religion and Arabic the official language,” he said.
An official from south Sudan’s main party criticised Bashir’s stance, saying it would encourage discrimination against minorities in the mainly Muslim north and deepen the country’s international isolation.
South Sudan, where most follow traditional beliefs and Christianity, is three weeks away from the scheduled start of the referendum on whether to declare independence.
The vote was promised in a 2005 peace deal that ended a north-south civil war and set up an interim constitution which limited sharia to the north and recognised “the cultural and social diversity of the Sudanese people.”
Analysts expect most southerners to choose independence in the poll, due to start on January 9 and last for a week.
Yasir Arman, from the Sudan People’s Liberation Movement , said Bashir’s statements would encourage repression in the north. “This type of discourse is preparing the ground for a police state. The north, whether alone or with the south, is an extremely diverse place.”
Arman said it was the north’s hardline stance that had pushed southerners towards separation. “If it continues like this it will encourage other areas like Darfur, the Nuba mountains and eastern Sudan to walk out as well,” he added, referring to areas on the peripheries of northern Sudan.
“It will also result in Sudan having worse relations with the outside world,” Arman said.
Southern leaders have said they are worried about how hundreds of thousands of southerners living in the north might be treated after a split.
Arman, Bashir’s main challenger in April presidential elections, is from the northern sector of the SPLM. He said his group would form a separate opposition party inside the north if the south seceded.
Bashir also defended police shown lashing a woman in footage that appeared on the video-sharing website YouTube. “If she is lashed according to sharia law there is no investigation. Why are some people ashamed? This is sharia,” he said.
Senior NCP member Nafie Ali Nafie said on Thursday efforts to keep the country united had failed, in the first acknowledgement from the northern elite that the south would probably secede.
Floggings carried out under Islamic law are almost a daily punishment in northern Sudan for crimes including drinking alcohol and adultery.