
Pongthep, a close aide to former prime minister Thaksin Shinawatra, said the government had earned its power undemocratically.
It drew breakaway MPs from the now-defunct People Power Party to join its ranks and also allowed a person related to the anti-Thaksin and anti-PPP government People's Alliance for Democracy to get a ministerial post, he said, referring to Foreign Minister Kasit Piromya.
Thaksin, on the other hand, is full of leadership and could help the country during times of crisis, he added.
Pongthep said he had talked to many businessmen, who are not satisfied with the economic team. They also questioned Abhisit's leadership and whether he is dominated by political groups within the Democrat and other parties.
"Having seen the faces of this Cabinet's members, especially the economic team in which the ministers come from coalition parties, many groups lack confidence in the team's unity and whether economic solutions will run in the same direction," he said.
Although the results of the by-elections on January 11 might not affect the make-up of the government coalition, they could indicate people's feelings toward the administration, he said, adding that the opposition parties are not ready for the by-elections.
Democrat Party executive Satit Pitutecha said it was too soon for Pongthep to be criticising the Abhisit administration.
"It [Pongthep's criticism] was made without first giving the government a chance to administrate the country during the political, social and economic crises," he said.
He said there were many aspects of leadership that Pongthep should have considered. Unlike Thaksin, he said, Abhisit is a prime minister who works for the whole country and has been accepted as an honest person.
Former prime minister Chuan Leekpai, who is now the Democrats' chief adviser, said Abhisit was likely to be a good prime minister.
Abhisit is young and smart, but he took on a life with the uncertainty and negative image of politics, Chuan said.
He said that besides Abhisit's determination to learn and solve problems, he had gained political experience from an early age. This makes him a professional politician.
"The country is facing many crises, including [national] unity. But it is not beyond the ability of determined politicians to solve these problems, nor beyond the ability of good bureaucrats to work out. People's cooperation and correct information would also contribute to the success," he said.
Chuan said Abhisit had never been a prime minister before, which was why some people still have less confidence in him than former premiers.
"I believe confidence in the prime minister will increase over time," he added.