* Border disputes unresolved
* Opposition leader says expects more protests
* Turabi cautions against transition to chaos
By Alexander Dziadosz
KHARTOUM, Oct 4 (Reuters) - Sudan and South Sudan will remain locked in conflict despite reaching a border security deal last week because they do not trust each other enough to resolve their biggest disputes, leading Sudanese opposition figure Hassan al-Turabi said.
The two African countries have been wrangling over contested areas along the border and other issues since breaking apart last year under a peace deal that ended decades of civil war.
Under pressure from the United Nations and African Union, the two agreed last Thursday to set up a demilitarized border zone and resume oil exports from the landlocked South after Juba shut them down in a row with Khartoum over transit fees.
But the deal failed to resolve problems like where to draw the final border, what to do with the disputed Abyei area and how to end rebellions in two Sudanese border states which Khartoum says Juba is backing, Turabi said.
"If we conclude a marriage we have to see to it that the bride and the groom trust each other ... There is no trust, and then serious problems are not settled," he told Reuters.
"They wanted to please the world only, because they are under pressure, and they can't stand the pressure from inside and the pressure from outside."
Turabi, one of Sudan's most influential politicians throughout the 1990s, dismissed the suggestion the deal was a boost to the government of President Omar Hassan al-Bashir, which has faced small protests over rising prices.
The government scaled back costly fuel subsidies in June to help plug a budget gap left when South Sudan took three-quarters of the country's oil output at independence, stoking already double-digit inflation.
Anti-government demonstrations erupted across Sudan when the spending cuts were announced, but petered out after a security crackdown and the start of the Muslim fasting month of Ramadan.
Turabi said he expected more protests. "It was a good experiment for us ... and the next time we do it, we want it to be continuous," he said.
CAUTION AGAINST CHAOS
Turabi was spiritual mentor to the Islamist leaders of the bloodless 1989 coup that brought Bashir to power, but he fell out with the president and has spent more than a decade in opposition. He has been arrested several times.
The 80-year-old Sorbonne-educated lawyer was a major force in introducing elements of Islamic law to Sudan's penal code and the decision to host militants like Osama bin Laden, which led the United States to impose sanctions in 1997.
Since joining the opposition he has been a stern critic of the government, going so far as to suggest Bashir should go to the International Criminal Court to face charges of masterminding war crimes in the western Darfur region.
Changing Sudan's government was the only way to ensure stable, friendly relations between the north and south, he said, adding the two were still culturally intertwined despite a war that killed some 2 million people.
"If there is democracy here - and there as well - culturally these two countries will immediately come close. We are closer to one another than the French and the Germans," Turabi said.
Yet he cautioned against moving from Bashir's government into "chaos," saying his Popular Congress Party was working with other opposition parties to devise an orderly transition.
"It's easy to destroy a house, it's very difficult to build a new one," he said. (Editing by Janet Lawrence)