By Tom Pfeiffer
AL-BAYDA, Libya (Reuters) - Rebels who have set up a National Libyan Council in east Libya are open to talks only on Muammar Gaddafi's resignation or exile to stop bloodshed, an aide to a top rebel figure said on Thursday.
Ahmed Jabreel, an aide to ex-justice minister Mustafa Abdel Jalil who heads the council now based in Benghazi, said air strikes to set up a "no-fly" zone were needed to help rebels topple Gaddafi, who has refused to step down despite a revolt.
"If there is any negotiation it will be on one single thing -- how Gaddafi is going to leave the country or step down so we can save lives. There is nothing else to negotiate," Jabreel, authorized to speak on Abdel Jalil's behalf, told Reuters.
"We are not going to negotiate any political solution. We want him put on trial, but if we don't give him an exit, we know more people will be killed," he said in al-Bayda, a coastal city in rebel-controlled eastern Libya.
The council has called for U.N.-backed air strikes against what they say are African mercenaries fighting for Gaddafi. Warplanes raided eastern towns on Thursday after launching a ground assault on Brega on Wednesday that rebels repulsed.
"I don't think Gaddafi is thinking any more about getting the east of Libya back. He is trying to keep whatever he has in his hands and find a political solution," Jabreel said.
Asked about Brega, Jabreel said: "On the ground, people are in control. We are saying we need airstrikes to impose a no-fly zone in Libya. With this, people will be able to defeat Gaddafi for sure."
"We have the weapons, the support, we have almost half of Libya that we can defend, so we are convinced that we can defeat any movement Gaddafi may make," he added.
Rebels have pushed the front line west from Brega and Gaddafi's forces have retreated to Ras Lanuf, 660 km (410 miles) east of Tripoli, rebel commanders and soldiers said.
"The military council in Benghazi started organizing themselves, they have not taken any decision to move to the west but they are organizing themselves so they can be ready for any development in the coming days," he said.
A council spokesman announced on Wednesday that Abdel Jalil would chair the 30-member body that will represent those rebelling against Gaddafi's 41-year rule.
But the spokesman said the council, which wants to move to Tripoli once Gaddafi falls, was not an interim government.
Jabreel, formerly a Libyan diplomat based in New York, said Abdel Jalil had been traveling around towns in the region to build support and a consensus about the council's plans.
"Everyone is saying the same thing. We want a constitution that divides between the three authorities, a civil participative state that is respected and respects other members of the international community," Jabreel said.
Rebel council spokesman Hafiz Ghoga has accused several African countries of sending troops to support Gaddafi and said there was evidence that Algeria, a fellow North African state, was playing a role. But Jabreel trod more cautiously.
"There is no proof at this stage that any government has been involved. I met some of the mercenaries a couple of years ago, they were given Libyan nationality," he said.
"That is why, when you see them, they don't look Libyan but have Libyan papers. The recruitment started a few years ago without the cooperation of any government," he added.
He also said there was stability in the eastern region, which has a history of revolting against Gaddafi's rule and which fell into rebel hands swiftly after protests erupted in mid-February.
"Security-wise things are very stable. We have not seen any instability in this part of Libya. People are very happy, very safe. There have been no clashes," Jabreel said.
(Writing by Edmund Blair in Cairo, editing by Tim Pearce)