African mediators and foreign partners Thursday produced a draft Declaration of Principle (DoP) to be adopted by the Khartoum government and the two Darfur rebel movements, but no progress could be made because of the row over Chad.
A spokesman for the SLM, which earlier said it would accept Chad only as observer, told AFP Sunday his group has now changed its stand on Chad.
"We support Chad as co-mediator because the country has played a very important role in the peace process in Darfur," Mahgoub Hussein said.
"Chad is here to help Darfur to achieve peace. We accept them in any capacity," he added.
But the JEM was still adamant in its opposition to Chad's participation.
"There won't be any progress in the peace talks until Chad is asked to withdraw. This has been our position and nothing will change it," JEM delegate Mohammed Tugod told AFP.
Chad has an eastern border with Darfur and hosts some 200,000 of the 2.4 million people estimated to have been displaced by the conflict.
The Abuja peace talks resumed after a six-month break over mutual accusations of ceasefire violations. The parties have yet to get together outside initial plenary sessions.
AU spokesman Nouredine Mezni said the mediators were working intensely to bring the warring parties to the negotiating table.
"We are going ahead with consultations to achieve a truce. It is not an easy task but the AU is trying its best," he said.
He said informal talks were taking place "at the highest level possible."
Mezni said African peacemakers have held series of negotiations with the parties in the last few days on a revised DoP.
"The SLM has given its submission in writing but the issue of Chad's participation which JEM raised two days ago is being addressed," he said.
"JEM negotiators have agreed to put their position in writing after which a formal meeting of the three warring parties to discuss and adopt the DoP will be convened," he assured.
He said broad-based consultations were going on to get the talks back on track involving the current AU chairman, the president of Nigeria.
"Last night, the special envoy to the Darfur peace talks Dr Salim Ahmed Salim, met with (Nigerian) President Olusegun Obasanjo to brief him on the progress of the talks and to also get his inputs on the issue of Chad," Mezni said, without elaborating.
"This is necessary because Chad has been part of the peace process in Darfur from the beginning," he said.
War broke out in February 2003 when an uprising representing the mainly black population of the region led Khartoum to unleash Arab militias known as Janjaweed, who have been accused of "ethnic cleansing", torture, rape and intimidation.
International pressure has increased to end the war that has claimed between 180,000 and 300,000 lives and displaced some 2.4 million people, especially since the resolution last year of a separate conflict which had engulfed oil-rich south Sudan for more than two decades.