In the year since he became Thai premier with no popular mandate, Abhisit Vejjajiva has underperformed on the domestic and regional stage and failed to reconcile a deeply divided nation, analysts say.

The Democrat party leader assumed power after winning a slim majority in a parliamentary vote on December 15 last year, following the downfall of a previous ruling party allied to ousted premier Thaksin Shinawatra.

After the constitutional court dissolved the People Power Party, prompting anti-Thaksin protesters to end a nine-day blockade of Bangkok's airports, the army helped to install a fragile coalition under the British-born Abhisit.

But analysts say the 45-year-old has failed to deliver on promises of national reconciliation in a kingdom still firmly split between supporters and foes of Thaksin, who was deposed in a 2006 coup.

"Thailand is further divided. It is further polarised," Thitinan Pongsudhirak, a political analyst at Bangkok's Chulalongkorn University, told AFP.

"In his acceptance speech he said he would be a prime minister for everyone. But in fact he has not reached out to the other side."

Since Abhisit took office he has regularly invoked the tough Internal Security Act (ISA) when faced with protests by thousands of anti-government "Red Shirts" -- Thaksin loyalists mainly from poor, rural areas in the north.

By contrast, during rallies by the rival, royalist "Yellow Shirts" who staged the airport siege that brought Abhisit to power, the prime minister has not enforced the ISA, Thitinan points out.

"The charges of double standards have been reinforced," he said, explaining that Abhisit had "leant back" on the yellows, a group tacitly supported by Thaksin-hating, Bangkok-based elites in the palace, bureaucracy and military.

Michael Montesano, a visiting research fellow at the Institute of Southeast Asian Studies in Singapore, said that equally worrying was the increased use under Abhisit of a strict lese majeste law. Under this law, insulting or defaming any royal family member is punishable by up to 15 years in jail.

"Those among Abhisit's foreign admirers who have always considered him a fellow liberal need to ask themselves how, if he's really such a liberal, he can preside over a government that so regularly uses this law," he said.

Paul Chambers, a senior research fellow in Thai politics at Germany's Heidelberg University, agreed the eloquent, Oxford-educated Abhisit had given Thailand "a presentable face on the international stage".

But he questioned the government's real effectiveness, for example in dealing with a separatist insurgency in the mainly Muslim south that has claimed 4,000 lives since January 2004.

"The Abhisit government has sought to place politics before the military... but any claims by the government that the insurgency is waning or that violence is down remain unsubstantiated," he said.

In terms of economic performance, Chambers recognised that Abhisit's approval of a one-time 2,000 baht (60-dollar) hand-out for the poor in the face of the recession "could be seen as a sort of plus for the government".

But while this seemed to ape Thaksin's populism, Thitinan said the Abhisit coalition had "got it wrong from the beginning" with stimulus packages that failed to address a desire for upward social mobility.

The twice-elected billionaire Thaksin has continued to loom large over the political landscape, despite living in self-imposed exile to avoid a two-year jail term for corruption.

When Cambodian Prime Minister Hun Sen appointed Thaksin economics adviser last month, angering Bangkok, the Thai premier showed a "cheap, anti-Cambodian" approach that "made clear that Abhisit is someone that loses his cool in international affairs," said Thitinan.

He said other members of the Association of Southeast Asian Nations also found Abhisit "very difficult to work with", and blamed a lack of success under Thailand's chairmanship of the body this year on his domestic preoccupations.

"Abhisit has played the role he was assigned -- to represent a group of interests whose politics are defined by hatred and fear of Thaksin -- and he has not yet grown larger than that role," Montesano said.