Syria's most prominent defector, General Manaf Tlass, has hinted that French secret agents helped him escape from Syria, where he had long been a member of President Bashar al-Assad's inner circle.

"The French [intelligence] services helped me get out of Syria and I thank them for that," Tlass, whose July 6 defection was hailed in the West as a major setback for Assad, said in a recorded interview broadcast on France's BFM television news channel on Monday.

A general in the elite Republican Guard charged with protecting the regime, Tlass is the son of former defence minister Mustafa Tlass, a close friend of Assad's late father and predecessor, Hafez al-Assad.

His defection was welcomed by the opposition umbrella group the Syrian National Council as an "enormous blow" to Assad.

Tlass, who fled Syria in July to France, where his sister, widow of a billionaire Saudi arms dealer, resides also said he was against any foreign intervention in Syria as it would not be able to bring down the government.

"It's up to the Syrian people to achieve victory by themselves," and foreign military intervention "could not provide a
solution" to the conflict, which began in March 2011, he said.

He called on outside powers to give the opposition "all the aid and support'' needed to topple Assad.

Western powers have said military action to secure safe zones in Syria was still an option, but they have shown little appetite for sending warplanes to Syria to protect safe havens or mount the kind of NATO bombing that helped Libyan rebels to topple Muammar Gaddafi last year.

"For me the situation in Libya is nothing like Syria, it is much more complicated. I don't see any foreign intervention being able to reach a solution," Tlass said.

Tlass is considered a potential candidate to pave the way for a peaceful transition both inside and outside Syria, but many opposition activists say he is tainted by his long service to Assad and the president's late father.

He has faced criticism from Syrian rebels, who say he and his 80-year-old father, who lives in Paris, should have made their positions clear at the very start of the anti-Assad uprising in March last year.

But Tlass said on Monday he had gone over to the rebel side "since the month of March", without specifying if he meant March this year or last year.

"Since the start of the revolution I had meetings with the revolutionaries ... and I had the feeling from the first days, the first months, that the regime was lying to everybody. That is why I at first defected while staying in my office," he said.

"My role is to unify and bring together our people. There are many groups working in our society whether the army, internally or externally," he said in Arabic. "We need to create a compact chain to bring this regime down."