By Opheera McDoom
KHARTOUM (Reuters) - A Darfur rebel unity congress, in jeopardy because the group's political leader refused to attend, could further divide the group and give the government the edge in the region's 2-1/2 year conflict, members said.

The congress in Darfur was called to elect new leadership to direct the Sudan Liberation Army (SLA), whose splits have worsened violence in Sudan's vast western region and stalled African Union-sponsored peace talks in Nigeria.

But the gathering of thousands of SLA members, who began arriving in the remote rebel-held area Haskanita last week, has so far failed to bring all sides together in part because SLA President Abdel Wahed Mohamed el-Nur has refused to attend.

"Nobody invited me to the conference," Wahed told Reuters on Tuesday from the mountainous headquarters of the rebel, Jabel Marra.

Mediators, charged with bridging the damaging gap between Nur and SLA Secretary General Minni Arcua Minnawi, remained at the congress site but had yet to meet with Minnawi.

"We are still waiting," Ahmed Abdel Shafiq Yagoub said. "The conference is still going on."

Nur is respected as the figurehead leader of the SLA, which launched a rebellion in early 2003, accusing Khartoum of monopolising wealth and power.

He returned to Darfur last week for the first time in more than 18 months, a move many say was to garner support ahead of the congress.

He said he would go instead to a U.S.-sponsored meeting in the Kenyan capital Nairobi on November 8, where he would meet SLA Secretary-General Minni Arcua Minnawi.

Nur and Minnawi have clashed many times over the past year. They have separate offices in the Eritrean capital Asmara and rarely present a united front.

Minnawi is aligned with the SLA's military, which turned out in force for the conference with thousands of fighters parading before him and commander-in-chief Juma'a Haggar.

Minnawi urged Nur to come and some members said if Nur did not attend the conference he would not be elected.

But some leaders at the congress expressed concern that it would go ahead and elect a new leadership without Nur's participation, which would create more factionalism.

GOVERNMENT GAINS BY SPLIT

"I don't think they should go ahead with the elections, as this would divide the leadership," the elderly humanitarian coordinator of the SLA Suleiman Adam Jamous told Reuters in Haskanita.

He said Nur would only take a few hundred fighters with him, but that any division was in the government's interest.

"They are too young," he said. "This struggle is older than them," he added, chiding them for putting their personality differences over the cause.

Tens of thousands have been killed and more than 2 million forced from their homes during the fighting, called genocide by the United States.

Khartoum, which is accused of arming Arab militias who raided Darfur villages, raping and murdering civilian population there, denies the charge. The International Criminal Court is investigating alleged war crimes in the area.

The United Nations, which had initially encouraged the meeting, was not represented at the congress because only one faction was participating.

"We are not going because it's not an all-inclusive conference," said U.N. spokeswoman Radhia Achouri.

But observers said that was taking Nur's side and instead the international community should push all leaders to attend the congress, called by the SLA grassroots.

"They are encouraging Nur's intransigence," said one international observer.

Tribal leader Tajeddin Ibrahim from Labado town in South Darfur said: "We want to see this movement democratised and for the leaders to unite and overcome their differences."