President Bashar al-Assad’s regime controls less than a third of Syria and the army should abandon him for the “side of the people”, the country’s former prime minister said.

Riyad Hijab, who became Syria’s most senior defector when he left his post 10 days ago, said the “corrupt” regime was suffering “spiritual and financial” collapse.

Delivering his first public remarks since changing sides, Mr Hijab spoke in the Jordanian capital, Amman, before the version of Syria’s national flag flown by the rebels. He used this appearance to predict Mr Assad’s downfall, praise the “revolution” and incite the army to turn on its commander.

“I assure you, from my experience and former position, that the regime is collapsing, spiritually and financially, as it escalates militarily,” said Mr Hijab, who served as a cabinet minister and provincial governor before Mr Assad made him prime minister in June.

“It [the regime] no longer controls more than 30 per cent of Syrian territory,” added Mr Hijab. “So let the shining revolution be completed.”

Mr Assad is believed to have massed thousands of troops for the assault on rebel forces in Aleppo, the commercial capital. To mobilise these units, he has effectively turned over large areas of rural Syria to the insurgents.

Mr Hijab made a direct appeal to the army to abandon Mr Assad. During the revolutions in Egypt and Tunisia last year, the armed forces chose not to intervene in order to prop up beleaguered regimes. The former prime minister urged Syrian soldiers to do the same.

“Syria is full of honourable officials and military leaders who are waiting for the chance to join the revolution,” he said. “I urge the army to follow the example of Egypt’s and Tunisia’s armies: take the side of people.”

As for his own decision to defect, Mr Hijab said this had been motivated by revulsion over the regime’s suppression of the uprising. He felt “pain in his soul” over the army’s assault on civilian areas and the loss of perhaps 20,000 lives during the last 17 months of bloodshed.

“I was powerless to stop the injustice,” he added. “It is my duty to wash my hands of this corrupt regime.”

Mr Hijab, a Sunni Muslim, served a government dominated by the minority Alawite sect. His home town of Deir el-Zour suffered grievously when it was attacked by the army, with large areas being destroyed by tanks.

Mr Hijab urged the rebel Free Syrian Army to “continue their fight against the regime as the Syrian people have high hopes and faith in you”.

Qatar and Saudi Arabia are believed to be directly arming the insurgents, while Turkey has provided bases and training camps on its territory. Mr Hijab thanked these countries, adding: “We call on them to continue their blessed efforts to support the people’s revolt.”

On the surface, his defection did not open a major fissure within the regime. Mr Hijab was not a household name in Syria. A civil servant rather than a politician, he wielded no independent authority. Real power in Syria lies in the hands of a few security chiefs, often members of the Assad family. For as long as they remain loyal and the army continues to obey orders, the president may be able to fight on.

More than 23,000 people have been killed in Syria since the start of the uprising in March last year, the British-based Syrian Observatory for Human Rights said on Tuesday. (© Copyright of Telegraph Media Group Limited 2012. 08/15/12)