Pressure has mounted on Syrian President Bashar al-Assad after a first senior diplomat, his ambassador to Baghdad, defected and Western powers drew up a 10-day sanctions ultimatum.
Syria's ambassador to Iraq, Nawaf Fares, announced he was joining a small but growing list of officials who have defected to the opposition, as the regime battles a near 16-month-old uprising.
In exclusive statement to Al Jazeera, Nawaf al-Fares said that his decision came in the wake of what he described as horrible massacre committed against the Syrian people by the regime.
"I announced my resignation as Syrian ambassador to Iraq as I also declare my defection from the Syrian Baath party," said Fares on Wednesday.
"I urge all honest members of this party to follow my path because the regime has turned it [the party] to an instrument to kill people and their aspiration to freedom."
Fares also called upon the military to join the ranks of the Syrian revolution, pointing out that such a move would help defend the homeland against any foreign enemy and "not the killing of the people".
He also urged all Syrians to come together and be patient in front of what he called attempts by the regime to divide them.
A veteran of Assad's rule who held senior positions under the late president Hafez al-Assad, Fares is from Deir Ezzor, the eastern city on the road to Iraq, which has been the scene of a ferocious military onslaught by Assad forces.
Unlike earlier defections, such as that of Manaf Tlas, a Syrian general and personal friend of Assad, Fares's defection deals a harsh blow to the Syrian government.
Reacting to the news, Jay Carney, the US spokesperson, said the defection of such a ranking Syrian official was evidence that Assad was losing his grip.
"Those around him, both in his inner circle and more broadly in the military and governmental leadership are beginning to assess Assad's chances of remaining in power," Carney said.
Fawaz Gerges, from the London School of Economics, told Al Jazeera that the latest development showed that people were losing confidence in the Assad regime.
"If you go outside Aleppo or Deraa or Hama, [the rebels] are extremely focused," Gerges said.
"But if you position the opposition outside Syria, then we're not really talking about an alternative to the Assad regime.
"The writing is not on the wall, but the signs tell me that time is not on the side of the Assad regime ... There's an economic war, psychological war. That's why the defection today represents a moral and political blow."
Mohamed Sermini, a member of the Syrian National Council (SNC), the main opposition umbrella group, described the ambassador's defection as the beginning.
"This is just the beginning of a series of defections on the diplomatic level. We are in touch with several ambassadors," said
Fares, a Sunni who is said to have close ties to Syrian security, is the second senior diplomat to quit the embattled government. The first was Bassam Imadi, who was the Syrian ambassador to Sweden until December.
Imadi, who is now a SNC member, told Al Jazeera from Rome that the defections of Fares and Tlas are an indication that people have started jumping ship after realising that the end of Assad is very near.
"We should consider him [Fares] as someone very close to the regime. But still he defected because I think he could not bear watching what is happening in Syria. We should also remember that he is also calling on other ambassadors to resign, which means that others will follow suit," said Imadi.
Threat of new sanctions
At the United Nations, Britain, France, Germany and the United States submitted a draft text that would give Assad 10 days to implement UN-Arab League envoy Kofi Annan's ceasefire plan or face tough new sanctions.
If Security Council members, including a reluctant Russia, approve it, the resolution would allow for non-military sanctions under Chapter VII of the UN charter if Syrian government forces keep up their offensive on cities.
The resolution condemns "the Syrian authorities' increasing use of heavy weapons, including indiscriminate shelling from tanks and helicopters".
Negotiations on the Western draft and a rival Russian resolution, which does not mention sanctions, are to start on Thursday in New York.
The draft calls for an "immediate" end to violence by government and opposition forces and demands that President Assad's troops return to barracks in line with the Annan plan and UN resolutions passed in April.
The resolution would renew the mandate of the UN Supervision Mission in Syria for 45 days, and calls on the mission to take on more political duties, moving away from monitoring a non-existent ceasefire.
'No traces of explosives'
Turkey meanwhile said it has found no traces of explosives on the wreckage of a fighter jet it has claimed was downed by Syria, raising new questions about the incident that inflamed cross-border tensions.
"No traces of explosives or flammable products were found on the debris recovered from the sea," a statement from Turkey's general staff said late on Wednesday, adding that other material was still being examined.
For the first time, the army also declined to use the term "shot down by Syria" instead referring to "our plane that Syria claimed to have destroyed."
Turkey has previously maintained that the F-4 Phantom was shot down in international airspace over the eastern Mediterranean by Syrian fire on June 22, further souring relations between the one-time allies.