The Islamic Movement, a social group at the heart of Sudan's ruling National Congress Party (NCP), is holding its first national conference since uprisings and civil war drove out authoritarian leaders around the region in 2011, Thursday.
While Islamists gained power through democratic elections in Egypt and Tunisia this year, a coup installed Sudan's Islamist regime 23 years ago – and it is still there.
Reformers charge that corruption and other problems have left the vast African nation's government Islamic only in name and question how much longer President Omar al-Bashir should remain in power.
Potential candidates to replace Bashir are jostling for influence within the Islamic Movement, said Khalid Tigani, an analyst and chief editor of the weekly economic newspaper Elaff.
"I think this is because we are approaching a change in power," said Tigani, a former activist in the National Islamic Front party which engineered the 1989 coup. Tigani now calls himself an independent Islamist.
The Islamic Movement is "one of the tools used by those who are in power to give themselves legitimacy among the Islamists, to continue controlling the government, the National Congress, in the name of Islam," he said.
Ali Osman Taha, a government vice president, has been the Islamic Movement's secretary general for two terms and is not eligible to run again.
Analysts say he is a possible successor to Bashir, who has announced he will step down as ruling party leader at an NCP congress late next year.
"A lot of people are saying 23 years is too long a time, and what's the difference between him and Mubarak and Assad?" said a Sudan analyst who asked for anonymity.
He was referring to ousted Egyptian president Hosni Mubarak and Syria's beleaguered President Bashar al-Assad.
Questions over Bashir's future were reinforced when, according to official media, he had his second minor operation in less than four months last week after an infection to his vocal cords.
He then appeared on television looking tired but healthy, and gave a typically fiery speech.
Hassan al-Turabi, a key figure behind the 1989 coup, sees a rivalry between Bashir and Taha.
"So both of them are competing" for control, along with others in the NCP, said Turabi, who believes Bashir wants to remain president to protect himself from arrest by the International Criminal Court.
The Hague-based court has indicted Bashir for war crimes, crimes against humanity and genocide allegedly committed in Sudan's far-western Darfur region, where a rebellion erupted in 2003.
Turabi broke with Bashir in a power struggle about a decade after the coup and formed his Islamist opposition party, the Popular Congress.
While only about 12 percent of NCP members come from the Islamic Movement, most of the party leadership belongs to the movement, said Islamic Movement senior member Amin Hassan Omer.
But "nothing specific" about succession will emerge from the conference, he predicted.
"I don't feel that there is a real power struggle in the Islamic Movement," said Omer, a state minister in the presidency.
But Mahjoub Mohamed Salih, publisher of the independent Al-Ayaam newspaper, said the conference would highlight a split between grassroots Islamists and NCP loyalists.
Some Islamists are now saying openly to the NCP: "You are just using Islam as a rationalisation for things which are un-Islamic," Salih said.
Turabi, the founder of the breakaway Popular Congress, calls it a "corrupt dictatorship, cruel dictatorship", which he does not want associated with Islam.
State minister in the presidency Omer said he expects such comments from critics but that it is "nonsense" to suggest there is widespread dissatisfaction among younger Islamists over corruption.
However, Sudan's Islamic regime has been linked to "so many bad things," leading to calls for reform from NCP youth and others, said self-described independent Islamist Tigani.
"So I think to some extent (the) Arab uprising is reflected here in the hopes for change in Sudan," he said.
Such hopes will be dashed, Tigani and Salih predicted, while Omer admitted reformers would be disappointed, despite "a general sense of urgency for change" in the Islamic Movement, including the need for a younger leadership.