In an interview Sudanese Islamist opposition leader Hassan al Turabi, a one-time key mentor turned bitter opponent of President Omar al-Bashir, warned that if Bashir failed to share power in the face of popular protests, it would lead to bloodshed.
"This country has known popular uprisings before," Turabi said, referring to popular revolts which toppled military regimes in the Arab world's largest country in 1964 and 1985.
"What happened in Tunisia is a reminder. This is likely to happen in Sudan," he said, referring to the month-long deadly protests that prompted veteran Tunisian strongman Zine El Abidine Ben Ali to take refuge in Saudi Arabia after 23 years of iron-fisted rule.
"If it doesn't, there will be a lot of bloodshed. The whole country is armed. These people don't demonstrate, they fight."
Turabi, who is suspected by the government of having links to the most heavily armed of the Darfur rebel factions, the Justice and Equality Movement (JEM), said he expected the western region where Khartoum has been fighting an eight-year rebellion would play a role.
"I'm quite sure if there's any uprising here, the Darfur region will be active," he said.
In May 2008, JEM fighters launched an unprecedented march on Khartoum, reaching the capital's twin city of Omdurman just across the Nile from the presidential palace before being repulsed with heavy losses.
Turabi, who was a key figure behind the 1989 coup that brought Bashir to power but has spent long periods in jail or under house arrest for his outspoken comments since the two men fell out in 1999, said the looming breakaway of the south after this month's independence vote was stoking concern in the north.
"The people of Sudan are shocked," he said of the week-long referendum that was the centrepiece of a 2005 peace agreement that ended a devastating 22-year civil war between north and south.
"They are really worried about the disintegration of their country," he said alluding to the civil war in Darfur and a 12-year rebellion in the east which ended with a still-fragile 2006 peace agreement.
"Sudan is not a small country like Tunisia but it is exposed to a risk of chaos worse than Somalia," he said, adding: "The concept of poverty is felt," following the adoption of a stinging austerity package by the government on January 5.
Political uncertainty, skyrocketing food prices and weak state finances have caused a sharp fall in the value of the Sudanese pound. Already saddled with heavy debt, the country has also exhausted its foreign currency reserves and is blighted by inflation.
On Sunday, opposition parties, including Turabi's Popular Congress Party, called a joint news conference to congratulate Tunisians and called for an "end to the totalitarian regime" in Khartoum.
The Islamist leader had told reporters in Qatar earlier this month that Sudanese opposition leaders were working on ways to overthrow Bashir's government peacefully.
"As dialogue with the regime took a long time, and after opposition leaders realised that the elections were hopeless... they have agreed to topple the regime," he said on January 3.